ArticlePDF AvailableLiterature Review

Romantic love: A mammalian brain system for mate choice

Authors:

Abstract and Figures

Mammals and birds regularly express mate preferences and make mate choices. Data on mate choice among mammals suggest that this behavioural 'attraction system' is associated with dopaminergic reward pathways in the brain. It has been proposed that intense romantic love, a human cross-cultural universal, is a developed form of this attraction system. To begin to determine the neural mechanisms associated with romantic attraction in humans, we used functional magnetic resonance imaging (fMRI) to study 17 people who were intensely 'in love'. Activation specific to the beloved occurred in the brainstem right ventral tegmental area and right postero-dorsal body of the caudate nucleus. These and other results suggest that dopaminergic reward and motivation pathways contribute to aspects of romantic love. We also used fMRI to study 15 men and women who had just been rejected in love. Preliminary analysis showed activity specific to the beloved in related regions of the reward system associated with monetary gambling for uncertain large gains and losses, and in regions of the lateral orbitofrontal cortex associated with theory of mind, obsessive/compulsive behaviours and controlling anger. These data contribute to our view that romantic love is one of the three primary brain systems that evolved in avian and mammalian species to direct reproduction. The sex drive evolved to motivate individuals to seek a range of mating partners; attraction evolved to motivate individuals to prefer and pursue specific partners; and attachment evolved to motivate individuals to remain together long enough to complete species-specific parenting duties. These three behavioural repertoires appear to be based on brain systems that are largely distinct yet interrelated, and they interact in specific ways to orchestrate reproduction, using both hormones and monoamines. Romantic attraction in humans and its antecedent in other mammalian species play a primary role: this neural mechanism motivates individuals to focus their courtship energy on specific others, thereby conserving valuable time and metabolic energy, and facilitating mate choice.
Content may be subject to copyright.
Romantic love: a mammalian brain
system for mate choice
Helen E. Fisher
1,
*
, Arthur Aron
2
and Lucy L. Brown
3
1
Depar tment of Anthropology, Rutgers University, 131 George Street, New Brunswick,
NJ 08901-1414, USA
2
Depar tment of Psychology, State University of New York, Stony Brook, NY 11794, USA
3
Depar tment of Neuroscience, Department of Neurology, Albert Einstein College of Medicine,
New Haven, CT 06519-130, USA
Mammals and birds regularly express mate preferences and make mate choices. Data on mate choice
among mammals suggest that this behavioural ‘attraction system’ is associated with dopaminergic
reward pathways in the brain. It has been proposed that intense romantic love, a human cross-
cultural universal, is a developed form of this attraction system. To begin to determine the neural
mechanisms associated with romantic attraction in humans, we used functional magnetic resonance
imaging (fMRI) to study 17 people who were intensely ‘in love’. Activation specific to the beloved
occurred in the brainstem right ventral tegmental area and right postero-dorsal body of the caudate
nucleus. These and other results suggest that dopaminergic reward and motivation pathways
contribute to aspects of romantic love. We also used fMRI to study 15 men and women who had just
been rejected in love. Preliminary analysis showed activity specific to the beloved in related regions of
the reward system associated with monetary gambling for uncertain large gains and losses, and in
regions of the lateral orbitofrontal cortex associated with theory of mind, obsessive/compulsive
behaviours and controlling anger. These data contribute to our view that romantic love is one of the
three primary brain systems that evolved in avian and mammalian species to direct reproduction. The
sex drive evolved to motivate individuals to seek a range of mating partners; attraction evolved to
motivate individuals to prefer and pursue specific partners; and attachment evolved to motivate
individuals to remain together long enough to complete species-specific parenting duties. These three
behavioural repertoires appear to be based on brain systems that are largely distinct yet interrelated,
and they interact in specific ways to orchestrate reproduction, using both hormones and
monoamines. Romantic attraction in humans and its antecedent in other mammalian species play
a primary role: this neural mechanism motivates individuals to focus their courtship energy on
specific others, thereby conserving valuable time and metabolic energy, and facilitating mate choice.
Keywords: mate choice; romantic love; dopamine; oxytocin; vasopressin; evolution
1. ROMANTIC LOVE: A MAMMALIAN BRAIN
SYSTEM FOR MATE CHOICE
Individuals of many species exhibit mate preferences
and focus their courtship energy on these favoured
conspecifics. The phenomenon of ‘courtship attrac-
tion’ is so common in nature that the ethological
literature regularly uses several terms to describe it,
including ‘female choice’, ‘mate preference’, ‘individ-
ual preference’, ‘favouritism’, ‘sexual choice’ and
‘selective proceptivity’ (Andersson 1994). Charles
Darwin regarded this phenomenon, what has become
known as mate choice’, as a central aspect of
intersexual selection, the type of sexual selection by
which individuals of one sex evolve traits that attract
members of the opposite sex (Darwin 1871/n.d).
Mammalian and avian species (as well as other
species) have evolved many physical and behavioural
characteristics by means of mate choice. The peacock’s
tail feathers are the standard example. But investi-
gations have focused on the traits that ‘display
producers’ have evolved to attract mates. The corre-
sponding neural mechanism by which ‘display choo-
sers’ become attracted to these traits and focus their
mating energy on particular preferred individuals,
thereby making a mate choice, has not been defined.
Therefore, it has been proposed (Miller 2000; Fisher
et al. 2002a,b) that two aspects of intersexual selection
evolved in tandem: (i) traits that evolved in the ‘display
producer’ to attract mates, and (ii) corresponding
neural mechanisms in the ‘display chooser’, the
viewer of the display, that evolved to enable him/her
to discriminate between various displays, become
attracted to some and pursue these specific preferred
individuals.
Several brain systems most probably operate in
tandem to orchestrate mate choice, including the
neural systems for sensory perception, memory, and
cognitive and emotional responses. But the specific
brain mechanism discussed in this review is the neural
mechanism that motivates the display chooser to pursue
a preferred mating partner, the courtship attraction
Phil. Trans. R. Soc. B (2006) 361, 2173–2186
doi:10.1098/rstb.2006.1938
Published online 13 November 2006
One contribution of 14 to a Theme Issue ‘The neurobiology of social
recognition, attraction and bonding’.
* Author for correspondence (helenfisher@helenfisher.com).
2173 This journal is q 2006 The Royal Society
system. Courtship attraction is characterized in
mammals by increased energy, focused attention,
obsessive following, affiliative gestures, possessive
mate guarding and motivation to win a preferred
mating partner (Fisher 2004).
A number of groups have reported that the basic
human motivations and emotions arise from distinct
systems of neural activity and that these brain systems
derive from mammalian precursors (Davidson 1994;
Panksepp 1998). Thus, it is parsimonious to suggest
that a mammalian brain mechanism for courtship
attraction is also active in Homo sapiens. Moreover,
because human romantic love (also known as passio-
nate love, obsessive love and ‘being in love’) is a
universal human phenomenon ( Jankowiak & Fischer
1992), because romantic love’s central characteristic is
mate preference and because ‘being in love’ exhibits
many of the other traits associated with mammalian
courtship attraction, it has been hypothesized that
human romantic love is a developed form of this
mammalian neural mechanism for mate choice (Fisher
1998). In most species, courtship attraction is brief,
lasting only for minutes, hours, days or weeks; in
humans, intense early stage romantic love can last
12–18 months (Marazziti et al. 1999) or more.
This review discusses the present evidence for this
brain system in mammals and humans, focusing on
recent neuroimaging studies of romantic love in
humans (Bartels & Zeki 2000, 2004; Aron et al.
2005; Fisher et al. 2005a,b). It examines how this
brain system varies from the sex drive and how it
changes across time (Aron et al. 2005). It also discusses
preliminary data on neural mechanisms associated with
romantic rejection (Fisher et al. 2005a,b). Finally, it
proposes that this brain system is one of the three
primary mating drives which interact in many ways and
which have evolved in mammalian and avian species to
direct various aspects of reproduction. (i) The sex drive
evolved to motivate individuals to seek copulation with
a range of partners, (ii) courtship attraction/romantic
love evolved to enable ‘display choosers’ to focus their
mating energy on specific mates, thereby conserving
courtship time and metabolic energy, and (iii) partner
attachment evolved to motivate mating individuals to
remain together long enough to perform species-
specific parental duties (Fisher 1998).
2. MAMMALIAN COURTSHIP ATTRACTION
‘It was evidently a case of love at first sight, for she swam
about the new-comer caressingly...with overtures of
affection’ (Darwin 1871/n.d.). Darwin was describing a
female Mallard duck. Blackbirds, thrush, black grouse,
pheasants, these and many other birds, were reported as
‘fell in love with one another’ (Darwin 1871/n.d.).
A myriad of other descriptions of courtship attrac-
tion have been reported by ethologists (Andersson
1994). Gladikas (1995) reports of a free-ranging
orangutan living in the Tanjung Putting Reserve,
Borneo, ‘The object of TP’s adoration was Priscilla
. I thought that TP would have chosen a more comely
female. But . TP was smitten with her . He couldn’t
take his eyes off her. He didn’t even bother to eat, so
enthralled was he by her balding charms’. Housing
conditions are likely to alter the display of mate
preferences among laboratory animals when not
presented with a choice, but free-ranging individuals
regularly exhibit sexual favouritism.
Yet despite hundreds of ethological descriptions of
courtship attraction in a wide array of mammalian and
avian species, ethologists have traditionally lumped this
motivation/emotion system together with the sex drive.
However, there are exceptions. Beach (1976) made a
distinction between the sex drive and the courtship
attraction, writing that the occurrence of copulation
depended as much on individual affinities and aver-
sions as upon the presence or absence of sex hormones
and that proceptive and receptive behaviour in the
female may depend upon different anatomical and
neurochemical systems in the brain. Hutchison &
Hutchison (1983) proposed that courtship entailed a
sequence of choices, each requiring different
mechanisms, and they questioned whether the sex
hormones had any specific role in the establishment
and expression of mating preferences. Pfaff (2002)
distinguishes between the hormone-dependent facili-
tation of sexual arousal and the expression of approach
and other courtship behaviours, regarding these as
distinct aspects of mating behaviour and physiology.
Kendrick & Dixson (1986) have shown that ante-
romedial hypothalamic lesions block proceptivity but
not receptivity in the female common marmoset.
Finally, Goodall (1986) reported that males of many
primate species ‘show clear-cut preferences for particu-
lar females, which may be independent of cycle stage’.
Various neurochemical mechanisms have also been
associated with courtship attraction. Darwin
hypothesized that female mate preferences arose from
their innate sense of beauty. But he (understandably)
offered no hypothesis regarding which specific neural
mechanisms might be involved (Darwin 1871/n.d.).
Miller (2000) noted that several faculties must have
evolved to discern and respond to the courtship traits of
display producers, referring to this constellation of
neural mechanisms as ‘mental machinery’ and ‘sexual
choice equipment’. Miller (2000) also distinguished
between ‘cold choosers’, such as insects that become
attracted to ornamental displays without any sensation
of pleasure, and ‘hot choosers’, animals whose choice
of mates is directed by subjective feelings of pleasure;
and he proposed that the endorphins may be involved
in the mate choices of hot choosers. Beach (1976)
suggested that the monoamines were involved in mate
preference, saying, ‘The mating behaviour of female
rats treated with monoamine receptor blocking agents
indicates that lordotic behaviour and soliciting
behaviour may be mediated by anatomically and
possibly neurochemically distinct systems’.
Present research supports Beach’s hypothesis. When
a female laboratory-maintained prairie vole (Microtus
ochrogaster) is mated with a male, she forms a distinct
preference for him associated with a 50% increase in
dopamine in the nucleus accumbens (Gingrich et al.
2000). When a dopamine antagonist is injected into the
accumbens, the female no longer prefers this partner
and when a female is injected with a dopamine agonist,
she begins to prefer the conspecific that is present at the
time of infusion, even if she has not mated with this
2174 H. E. Fisher and others Romantic love
Phil. Trans. R. Soc. B (2006)
male (Wang et al. 1999; Gingrich et al. 2000). An
increase in central dopamine is also associated with
courtship attraction in female sheep (Fabre-Nys 1997,
1998). In male rats, too, increased striatal dopamine
release has been shown in response to the presence of a
receptive female rat (Robinson et al. 2002; Montague
et al. 2004).
Recent data on several peptides also suggest that
central dopamine plays a role in regulating mate
preference. Kendrick & Dixson (1985) showed that in
marmosets, luteinizing hormone-releasing hormone
specifically facilitated female proceptive behaviours,
and oxytocin and vasopressin have been shown to
facilitate social recognition in mammalian species.
All of these peptides facilitate monoamine release
(Kendrick 2000). Therefore, it has been suggested
that mate preference may be influenced as these
peptides rewire brain circuits so that sensory and
other stimuli from specific individuals have more
potent effects on monoamine release, particularly
release of dopamine in brain reward centres (Lim
et al. 2004).
The extensive ethological literature on sexually
dimorphic traits that evolved to attract mates, in
conjunction with the above physiological data on
mate preference in several species, suggests that
intersexual selection involves interactions between the
display traits of display producers and a brain system
for mate preference in display choosers, courtship
attraction. Moreover, the data suggest that the brain
system for courtship attraction is distinct from, yet
operates in tandem with, the sex drive to orchestrate
proceptivity in birds and mammals. Finally, the
dopaminergic reward pathways may be involved.
3. HUMAN ROMAN TIC LOVE
It was appropriate to investigate this brain system in
Homo sapiens for several reasons. Foremost, intense
romantic love is a cross-cultural universal. In a survey
of 166 societies, Jankowiak & Fischer (1992) found
evidence of romantic love in 147 of them. No negative
data were found; in the 19 remaining cultures,
anthropologists had failed to ask the appropriate
questions; all were cases of ethnographic oversight.
Jankowiak & Fischer (1992) concluded that romantic
love constitutes a ‘human universal . or near universal’.
Moreover, romantic love is associated with a specific
set of physiological, psychological and behavioural
traits (Tennov 1979; Hatfield & Sprecher 1986; Shaver
et al. 1987; Hatfield et al. 1988; Harris & Christenfeld
1996; Fisher 1998; Gonzaga et al. 2001); and most of
these traits are also characteristic of mammalian
courtship attraction, including increased energy, focused
attention, obsessive following, affiliative gestures,
possessive mate guarding, goal-oriented behaviours
and motivation to win a preferred mating partner
(Fisher et al. 2002a,b; Fisher 2004).
Romantic love begins as an individual starts to
regard another individual as special and unique. The
lover then focuses his/her attention on the beloved,
aggrandizing the beloved’s worthy traits and over-
looking or minimizing his/her flaws. The lover
expresses increased energy, ecstasy when the love affair
is going well and mood swings into despair during times
of adversity. Adversity and barriers heighten romantic
passion, what has been referred to as ‘frustration
attraction’ (Fisher 2004). The lover suffers ‘separation
anxiety’ when apart from the beloved and a host of
sympathetic nervous system reactions when with the
beloved, including sweating and a pounding heart.
Lovers are emotionally dependent; they change their
priorities and daily habits to remain in contact with
and/or impress the beloved. Smitten humans also
exhibit empathy for the beloved; many are willing to
sacrifice, even die for this ‘special’ other. The lover
expresses sexual desire for the beloved, as well as
intense sexual possessiveness, mate guarding. Yet the
lover’s craving for emotional union supersedes his/her
craving for sexual union with the beloved. Most
characteristic, the lover thinks obsessively about the
beloved, ‘intrusive thinking’. Rejected lovers first
experience a phase of protest, during which they try
to win back the beloved and often feel abandonment
rage; then they move into the second stage of rejection,
associated with resignation and despair. Romantic love
is also involuntary, difficult to control and generally
impermanent.
Since romantic love shares many characteristics
with mammalian courtship attraction, it has been
hypothesized that this human preference system
would also be associated with the monoamines,
specifically elevated activity of central dopamine
and/or central norepinephrine (Liebowitz 1983; Fisher
1998).
4. ROMANTIC LOVE: FUNCTIONAL MAGNETIC
RESONANCE IMAGING RESEARCH
To investigate the constellation of neural correlates
associated with romantic love, Fisher, Aron, Brown and
colleagues recruited 10 women and 7 men who were
intensely in love. The age range was 18–26 years
(MZ20.6; medianZ21); the reported duration of ‘being
in love’ was 1–17 months (MZ7.4; medianZ7). Each
participant was orally interviewed in a semi-structured
format to establish the duration, intensity and range of
his/her feelings of romantic love. Each also completed
the Passionate Love Scale (PLS), a 9-point Likert scale
self-report questionnaire which measures traits com-
monly associated with romantic love (Hatfield &
Sprecher 1986; Cronbach’s alpha for questionnaire
reliability in this studyZ0.81; Cronbach 1951).
A preliminary investigation had identified a photo-
graph of the beloved as an effective stimulus for eliciting
feelings of intense romantic love (Mashek et al. 2000).
Thus, the protocol employed photographs and con-
sisted of four tasks presented in an alternating block
design: for 30 s, each participant viewed a photo of his/
her beloved (positive stimulus); for the following 40 s,
each performed a countback distraction task; for the
following 30 s, each viewed a photograph of an
emotionally neutral acquaintance (neutral stimulus);
and for the following 20 s, each performed a similar
countback task. The countback task involved viewing a
large number, such as 8421, and mentally counting
backwards (beginning with this number) in increments
of seven. We included the countback task to decrease
Romantic love H. E. Fisher and others 2175
Phil. Trans. R. Soc. B (2006)
the carry-over effect after the participant viewed the
positive stimulus because it is difficult to quell intense
feelings of romantic love. This four-part sequence (or a
counterbalanced version beginning with the neutral
stimulus) was repeated six times; the total stimulus
protocol was 720 s (12 min). Pre-scanning instructions
were to think about a non-sexual euphoric experience
with the beloved; post-scanning interviews established
that the participants had engaged in romantic thinking
and feeling.
Group activation specific to the beloved occurred in
several regions, including the right ventral tegmental
area (VTA) localized in the region of A10 dopamine
cells (Aron et al. 2005). The VTA is a central region of
the brain’s reward system (Wise 1996; Schultz 2000;
Martin-Soelch et al. 2001), associated with pleasure,
general arousal, focused attention and motivation to
pursue and acquire rewards (Schultz 2000; Delgado
et al. 2000; Elliot et al. 2003).
The VTA sends projections to several brain
regions (Gerfen et al . 1987; Oades & Halliday 1987;
Williams & Goldman-Rakic 1998), including the
caudate nucleus where we also found group activations,
specifically in the right medial and postero-dorsal body
(Aron et al. 2005). The caudate plays a role in reward
detection and expectation, the representation of goals
and the integration of sensory inputs to prepare for
action (e.g. Schultz 2000; Martin-Soelch et al. 2001;
Lauwereyns et al. 2002; O’Doherty et al. 2002). Zald
et al. (2004) found that predictable monetary reward
presentation caused dopamine release in the medial
caudate body where we found activation.
Using functional magnetic resonance imaging
(fMRI), Bartels & Zeki (2000) also investigated brain
activity in 17 men and women who reported being
‘truly, deeply and madly in love’. Eleven were women;
all looked at a photograph of his/her beloved, as well as
photographs of three friends of similar age, sex and
length of friendship. But the participants in that study
had been in love substantially longer than those in our
study (28.8 months versus 7.4 months t[32]Z4.28,
p!0.001). They were also less intensely in love. This
was established because both study groups were
(serendipitously) administered the same questionnaire
on romantic love, the PLS (respective scores were 7.55
versus 8.54, t[31]Z3.91, p!0.001). In spite of these
differences in protocol, Bartels & Zeki (2000, 2004)
found activity in regions of the ventral tegmental area
and caudate nucleus, as we did.
These data are consistent with the above animal
literature, suggesting that mesolimbic dopamine
pathways in the reward system of the brain play a role
in the pleasurable feelings, focused attention,
motivation and goal-oriented behaviours associated
with romantic love. However, activation of subcortical
dopaminergic pathways of the VTA and caudate
nucleus may comprise only the ‘general arousal’
component (Pfaff 1999) of this brain system for mate
preference and mate pursuit (Fisher 2004).
Other neurotransmitters are likely to be involved,
including glutamate in the mesocortical system, owing
to their role in the release of dopamine in the VTA
(Legault & Wise 1999) and/or their fast signals in the
prefrontal cortex regarding reward (Lavin et al. 2005).
Central norepinephrine may also be associated with
courtship attraction (Fisher 1998). This was
hypothesized because increased activity of nor-
epinephrine generally produces alertness, energy,
sleeplessness and loss of appetite (Coull 1998; Robbins
et al. 1998), increased attention (Posner & Peterson
1990) and increased memory for new stimuli (Griffin &
Taylor 1995), some of the primary characteristics of
human romantic love (Tennov 1979; Hatfield &
Sprecher 1986; Fisher 2004). As norepinephrine is
also associated with peripheral sympathetic nervous
system responses, including increased heart rate,
sweating and trembling, central norepinephrine may
contribute to these aspects of romantic love/courtship
attraction as well (Fisher 1998).
The above data suggest that mammalian courtship
attraction and human romantic love are associated with
dopaminergic reward pathways in the brain. These data
also support the hypothesis that romantic love is
distinct from the sex drive (Aron & Aron 1991; Fisher
1998).
5. THE SEX DRIVE
The sex drive is characterized by the urge for sexual
gratification. It is associated with the androgens and
oestrogens in non-primate mammalian species and
primarily with the androgens in many primates,
especially humans (Edwards & Booth 1994; Sherwin
1994; Van Goozen et al. 1997). Humans with higher
circulating levels of testosterone tend to engage in more
sexual activity (Edwards & Booth 1994; Sherwin
1994). Women tend to feel more sexual desire during
andaroundovulation,whentestosteroneactivity
increases (Van Goozen et al. 1997). Both sexes have
fewer sexual fantasies, masturbate less regularly and
engage in less intercourse as levels of the androgens
decline with age (Edwards & Booth 1994).
The balance between the androgens, oestrogens and
other bodily systems, as well as childhood and adult
experiences and a host of other biological and
environmental factors play a role in when, where and
how often individuals express the sex drive (Nyborg
1994). Nevertheless, the androgens are central to the
sex drive and these gonadal and adrenal hormones have
not been associated with human romantic love. More-
over, when humans self-administer androgens to boost
sex drive, they do not report that they fall in love. These
two neural systems do not always act in tandem in
Homo sapiens.
Several fMRI studies support the hypothesis that the
sex drive is associated with specific networks of brain
activation and that these networks are largely distinct
from those associated with human romantic love/
mammalian courtship attraction. Arnow et al. (2002)
reports that when young male heterosexual subjects
look at erotic video material while wearing a custom-
built pneumatic pressure cuff around the penis, their
sexual arousal is associated with strong activations in
the right subinsular region, including the claustrum,
left caudate and putamen, right middle occipital/
middle temporal gyri, bilateral cingulate gyrus, right
sensorimotor and pre-motor regions, and right
hypothalamus.
2176 H. E. Fisher and others Romantic love
Phil. Trans. R. Soc. B (2006)
Using fMRI, Beauregard et al. (2001) measured
brain activation in men as they viewed erotic film
excerpts. Activations occurred in limbic and paralimbic
structures, including the right amygdala, right
anterior temporal pole and hypothalamus. Using
fMRI, Karama et al. (2002) also recorded brain activity
while men and women viewed erotic film excerpts.
Activity increased in the anterior cingulate, medial
prefrontal cortex, orbitofrontal cortex, insula and
occipitotemporal cortices, as well as in the amygdala
and ventral striatum. Men showed activation in the
thalamus and significantly greater activation than
women in the hypothalamus, specifically in a sexually
dimorphic area associated with sexual arousal and
behaviour. Animal studies also indicate that several
brain structures are associated with the sex drive and
sexual expression, including the medial amygdala,
medial preoptic area, paraventricular nucleus and
periaqueductal gray (PAG; Heaton 2000), as well as
the septum and the ventromedial hypothalamus
(Dixson 1998).
Although the neural regions associated with the sex
drive overlap those associated with courtship attrac-
tion, these two neural systems show many differences,
suggesting that the primary brain system for the sex
drive is distinct from the brain system associated with
human romantic love (Aron & Aron 1991; Fisher
1998). Anecdotal behavioural data in humans support
this hypothesis. (i) The sex drive is focused on a specific
goal, sexual union with another, and romantic love is
focused on a different goal, emotional union with
another. (ii) The sex drive is often expressed towards a
range of individuals and romantic love is focused on one
particular individual. (iii) The sex drive is often
temporarily quelled when satisfied and romantic love
does not decrease with coitus and often persists
unabated for months, even years. (iv) Most liberated
adults have engaged in coitus with individuals for
whom they felt no romantic love and many have also
been ‘in love’ with someone with whom they have had
no physical contact.
Several lines of investigation indicate that the sex
drive and the courtship attraction/romantic love are
distinct neural systems, designed to orchestrate
different aspects of the reproductive process. The sex
drive enables individuals to initiate courtship and
mating with a range of partners; courtship attraction/
romantic love motivates them to focus their mating
energy on specific individuals, thereby conserving time
and metabolic energy.
Nevertheless, the brain systems for the sex drive and
the courtship attraction regularly interact to coordinate
mammalian mate choice.
6. THE SEX DRIVE AND MATE PREFERENCE:
INTERACTIONS
The biological relationships between the sex drive and
the courtship attraction are most likely dose dependent
and variable, depending on which brain regions are
involved and many other biological and environmental
factors. However, data suggest that these brain systems
have a positive correlation.
Animal studies indicate that elevated activity of
dopaminergic pathways can stimulate a cascade of
reactions, including the release of testosterone and
oestrogen (Wenkstern et al. 1993; Kawashima &Takagi
1994; Ferrari & Giuliana 1995; Hull et al. 1995, 1997,
2002; Szezypka et al. 1998; Wersinger & Rissman
2000). Likewise, increasing levels of testosterone and
oestrogen promote dopamine release (Hull et al. 1999;
Auger et al. 2001; Becker et al. 2001; Appararundaram
et al. 2002; Creutz & Kritzer 2002; Pfaff 2005). When a
male rat is placed in an adjacent cage, where he can see
or smell an oestrous female, activity of central
dopamine increases and contributes to sexual arousal
and pursuit of the female (West et al. 1992; Wenkstern
et al. 1993; Hull et al . 1995, 1997, 2002). When the
barrier is removed and the male is allowed to copulate,
activity of dopamine continues to rise in the medial
preoptic area (Hull et al. 1995). When dopamine is
injected into specific brain regions of the male rat, the
infusion stimulates copulatory behaviour (Ferrari &
Giuliana 1995). Blocking the activities of central
dopamine in rats diminishes several proceptive sexual
behaviours, including hopping and darting (Herbert
1996). Finally, electrochemical studies in male rats
show increased dopamine release in the dorsal and the
ventral striatum in response to the presence of a
receptive female rat (Robinson et al. 2002; Montague
et al. 2004). Pfaff (2005) reports that in male rats,
dopamine increases male sexual behaviour in at least
three ways: it increases sexual arousal and courtship
behaviour; it potentiates the motor acts of mounting;
and it facilitates genital responses to stimulation.
This positive relationship between elevated activity
of central dopamine, elevated sex steroids and elevated
sexual arousal and sexual performance (Herbert 1996;
Fiorino et al. 1997; Liu et al. 1998; Pfaff 2005) also
occurs in humans (Walker et al. 1993; Clayton et al.
2000; Heaton 2000). When individuals exhibiting
hypoactive sexual desire disorder are treated with
dopamine-enhancing medications, libido improves
(Segraves et al. 2001). When patients suffering from
depression take drugs that elevate central dopamine
activity, their sex drive often improves (Walker et al.
1993; Ascher et al. 1995; Coleman et al. 1999). In fact,
since elevated activity of central serotonin is inhibitory
to the sex drive (Rosen et al. 1999; Montejo et al. 2001),
some patients taking serotonin-enhancing antidepress-
ants supplement this therapy with medications that
elevate the activity of dopamine (and norepinephrine)
solely to maintain or elevate sexual appetite and arousal
(Walker et al. 1993; Ascher et al. 1995; Coleman et al.
1999; Rosen et al. 1999).
Animal studies indicate that norepinephrine is also
positively linked with sexual motivation and sexual
arousal (Van Bockstaele et al. 1989; Clayton et al. 2002;
Fraley 2002; Pfaff 2005). When a female prairie vole is
exposed to a drop of male urine on the upper lip,
norepinephrine in the olfactory bulb contributes to the
release of oestrogen and concomitant proceptive
behaviour (Dluzen et al.1981). The reverse also
occurs; oestradiol and progesterone contribute to the
release of norepinephrine in the hypothalamus to
produce lordosis in rats (Etgen et al. 1999). Moreover,
when ovariectomized, sexually receptive female rats
Romantic love H. E. Fisher and others 2177
Phil. Trans. R. Soc. B (2006)
receive injections of oestrogen and are then permitted
to mate, copulation produces the release of nor-
epinephrine in the lateral ventromedial hypothalamus
(Etgen & Morales 2002). Drug users attest to this
positive chemical relationship between norepinephrine
and the sex drive. In the right oral dose, amphetamines
(norepinephrine and dopamine agonists) enhance
sexual desire (Buffum et al. 1988).
The complex interaction between these catechol-
amines and gonadal hormones suggests why the sex
drive and the courtship attraction have traditionally
been lumped into a single behavioural category,
proceptivity. Instead, these distinct neural systems
appear to work in tandem to enable display choosers
to explore an array of mating partners, focus their
courtship attention on preferred individuals and then
sustain attraction and sexual arousal long enough to
complete species-specific mating behaviours.
7. PARTNER ATTACHMENT
The full array of brain systems associated with court-
ship, mating and parenting and the interactions
between these brain systems need further investigation
(Fisher & Thomson in press). Nevertheless, the
available literature suggests that at least three distinct,
yet interrelated neural systems play a role in reproduc-
tion: the sex drive, courtship attraction and partner
attachment. Each of these motivation/emotion systems
is associated with a different behavioural repertoire,
each is associated with a different and dynamic
constellation of neural correlates and each evolved to
direct a different aspect of reproduction (Fisher 1998).
The relationship between courtship attraction/roman-
tic love and the sex drive has been discussed above, and
partner attachment is considered next.
Partner attachment, or pairbonding, in birds and
mammals is characterized by mutual territory defence
and/or nest building, mutual feeding and grooming,
maintenance of close proximity, separation anxiety,
shared parental chores and affiliative behaviours. The
ethological literature commonly infers that this con-
stellation of attachment behaviours associated with
pairbonding evolved primarily to motivate mating
partners to sustain an affiliative connection long
enough to complete species-specific parental duties.
This parental attachment system has been associated
with the activity of the neuropeptides, oxytocin (OT) in
the nucleus accumbens and arginine vasopressin (AVP)
in the ventral pallidum (Carter 1992; Winslow et al.
1993; Wang et al. 1994; Carter et al. 1997; Yo u n g et al.
1998; Lim & Young 2004; Lim et al. 2004), although
the brain’s opioid system (Moles et al. 2004) and other
neural systems are involved as well (Kendrick 2000).
Bowlby (1969, 1973) and Ainsworth et al. (1978)
proposed that, to promote survival of the young,
primates have evolved an innate attachment system
designed to motivate infants to seek comfort and safety
from their primary caregiver, generally their mother.
More recently, researchers have emphasized that this
attachment system remains active throughout their life
and serves as a foundation for attachment between
spouses as they raise children (Hazan & Shaver 1987;
Hazan & Diamond 2000). Data from the Demographic
Yearbooks of the United Nations on 97 societies
suggest the prevalence of this attachment system in
humans. Approximately 93.1% of women and 91.8%
of men marry by age 49 (Fisher 1992). Pairbonding
and attachment behaviours are central aspects of the
multi-part human reproductive strategy (Fisher 1992).
Hatfield (1988) refers to feelings of attachment as
companionate love, which she defines as ‘a feeling of
happy togetherness with someone whose life has
become deeply entwined with yours’. Extensive
research has been done on this attachment system in
adults (Fraley & Shaver 2000), but this literature does
not regularly distinguish between feelings of attach-
ment and feelings of romantic love (Aron et al. 2006).
However, cross-cultural and historical data indicate
that people in other societies and centuries do
distinguish between feelings of romantic love and
attachment.
Nisa, a !Kung Bushman woman of the Kalahari
Desert, Botswana, reported, ‘When two people are first
together, their hearts are on fire and their passion is
very great. After a while, the fire cools and that’s how it
stays. They continue to love each other, but it’s in a
different way–-warm and dependable’ (Shostak 1981).
The Taita of Kenya say that love comes in two forms, an
irresistible longing, a ‘kind of sickness’, and a deep
enduring affection for another (Bell 1995). In Korea,
‘sarang’ is a word close to the western concept of
romantic love, while ‘chong’ is more like feelings of
long-term attachment; Abigail Adams, wife of Amer-
ica’s second president, distinguished these feelings
when writing to John Adams in 1793, ‘Years subdue
the ardor of passion, but in lieu thereof friendship and
affection deep-rooted subsists, which defies the ravages
of time’ (McCullough 2001).
Current brain imaging investigations in humans and
animal studies indicate some of the neural correlates of
this attachment mechanism. These data also suggest
that the neural correlates for attachment are distinct
from those for early-stage intense romantic love in
humans and courtship attraction in other mammalian
species, yet these two brain systems interact.
8. NEUROIMAGING AND ANIMAL STUDIES
OF ATTACHMENT
As discussed earlier, using fMRI, Bartels & Zeki
(2000) studied 17 men and women who were in love.
However, their subjects were in love for an average of
28.8 months, a considerably longer period of time
compared with our participants who were in love for
an average of 7.4 months (Aron et al. 2005); their
subjects were less passionately in love (Aron et al.
2005). Their participants also exhibited activity in
several brain regions where our subjects showed none,
including the anterior cingulate cortex and mid-
insular cortex.
These varying results stimulated us to examine the
subset of our subjects in longer relationships, speci-
fically those who were in love between 8 and 17
months. In our subset of individuals in longer
relationships, several regions showed activations,
including the right anterior and posterior cingulate
cortex, and right mid-insular cortex (Aron et al. 2005).
2178 H. E. Fisher and others Romantic love
Phil. Trans. R. Soc. B (2006)
Thus, we confirmed Bartels & Zeki’s (2000) findings
that the anterior cingulate and insular cortex are
involved in longer term love relationships.
More relevant to this discussion, we also found
activation in the ventral putamen/pallidum (Aron et al.
2005). Activity in this region, associated with a specific
distribution pattern of vasopressin (V1a) receptors, has
been linked with pairbonding and attachment
behaviours in monogamous prairie voles (Lim &
Young 2004; Lim et al. 2004), monogamous California
mice and monogamous marmosets, whereas promiscu-
ous white-footed mice and promiscuous rhesus mon-
keys do not express pairbonding/attachment
behaviours or this distribution of V1a receptors in the
ventral pallidum (Wan g et al. 1997; Young et al. 1997;
Bester-Meredith et al. 1999; Young 1999). Hence,
activity in the ventral pallidum is greater in longer term
human relationships than in shorter ones and activity in
the ventral pallidum, specifically associated with
vasopressin, is evident in other pairbonding/attaching
mammals.
But vasopressin activity in the ventral pallidum also
affects partner preference, a central characteristic of
mammalian courtship attraction and human romantic
love. Lim & Young (2004) report that arginine
vasopressin antagonists infused into the ventral palli-
dum prevented partner preference formation among
male prairie voles. Yet they also report that V1aR
activation in this region is necessary for pairbond
formation (Lim & Young 2004).
Activity of central oxytocin in the nucleus accum-
bens also contributes to both pairbonding and partner
preference (Lim et al. 2004). Williams et al. (1994)
report that when oxytocin was administered intracer-
ebroventricularly, ovariectomized female prairie voles
preferred the partner who was present at the time of
infusion; and Lim, Murphy and Young report that
when an oxytocin receptor (OTR) antagonist is infused
directly into the nucleus accumbens of a female prairie
vole, this antagonist blocks partner preference forma-
tion (Yo u n g et al. 2001; Lim et al. 2004). Yet they also
conclude that among monogamous prairie voles, OTRs
and vasopressin V1a receptors (V1aR) in the ventral
forebrain play critical roles in the formation of
pairbonds.
Research on the genetic basis of pairbonding also
lumps partner preference and attachment behaviours.
Pitkow et al (2001) reported that structural differences
in the V1 receptor gene of socially monogamous male
voles (as opposed to asocial promiscuous voles)
increased levels of the expression of this receptor in
the ventral pallidum; moreover, these males also
exhibited heightened levels of social affiliation. They
formed a preference for a specific female and began to
cohabit with her, even though they had not mated with
this female. Lim, Young and colleagues report that
when they transfected this genetic variant (the monog-
amous version) into the pallidum of meadow voles, an
asocial promiscuous species, vasopressin receptors
were upregulated; each male also began to fixate on a
par ticular female and mate exclusively with her, even
though other females were available (Lim et al. 2004).
The activities of central oxytocin and vasopressin
have been associated with both partner preference and
attachment behaviours, while dopaminergic pathways
have been associated more specifically with partner
preference. So Lim et al. (2004) integrate these data,
proposing that when monogamous prairie voles and
other pairbonding creatures engage in sex, copulation
triggers the activity of vasopressin in the ventral
pallidum and oxytocin in the nucleus accumbens and
facilitates dopamine release in these reward regions,
which motivates males and females to prefer a current
mating partner and initiates attachment/pairbonding
behaviours. Moreover, males of promiscuous species
(who lack one link in this chain for encoding the V1a
receptor for vasopressin in the ventral pallidum) most
probably feel attraction, but do not associate this
pleasurable feeling with their specific mating partner so
they do not initiate a longer term attachment. In
species that do not form these bonds, this relationship
with dopamine reward centres is much weaker
(Kendrick 2000).
Like the brain systems for the sex drive and the
courtship attraction, the neural mechanism for
attachment is complex, flexible, varies in its threshold
and intensity and is most likely integrated with many
other brain systems (Kendrick 2000), probably
including the opioids (Moles et al. 2004). Never-
theless, the above data suggest that the neural systems
for courtship attraction and partner attachment work
in tandem in a pairbonding species, motivating
individuals to prefer a specific mating partner and
also motivating them to form an attachment to this
mate. These data also suggest that courtship attrac-
tion and partner attachment can operate indepen-
dently in non-monogamous species, enabling
individuals to prefer specific mating partners yet
avoid long-term attachments.
Data on the neural correlates of maternal love
support the proposition that feelings of attachment
and feelings of romantic love are distinct yet inter-
related neural systems. Bartels & Zeki (2004) used
fMRI to measure brain activity in mothers while each
looked at a photo of her own infant, an infant with
whom she was acquainted, an adult best friend and an
adult acquaintance. They then compared these data on
the neural mechanisms associated with maternal
attachment with their data on the neural correlates of
(later stage) romantic love (Bartels & Zeki 2000).
Maternal love activated several specific brain regions
that differed from those associated with romantic love,
including the lateral orbitofrontal cortex and the PAG.
Maternal love also activated some brain regions that
were the same as those activated by romantic love,
including regions of the medial insula, anterior
cingulate gyrus and caudate nucleus. Finally, activity
associated with maternal love and romantic love
overlapped in brain areas rich in oxytocin and
vasopressin receptors, including the substantia nigra
(Bartels & Zeki 2004).
The neural flexibility of these brain systems for
reproduction and their interactions with one another
and other brain systems are complex (Kendrick 2000).
For example, central dopamine (and norepinephrine)
can stimulate the release of oxytocin and vasopressin in
neurohypophyseal tissues (Kendrick et al.1992;
Ginsberg et al. 1994; Galfi et al. 2001); but increasing
Romantic love H. E. Fisher and others 2179
Phil. Trans. R. Soc. B (2006)
activity of central dopamine can also inhibit release of
central oxytocin (Seybold et al. 1978; Vizi & Volbekas
1980). Increasing activity of central oxytocin can
stimulate release of norepinephrine and dopamine
(Kendrick 2000) or interfere with dopamine and
norepinephrine pathways (Schwarzberg et al. 1981;
Kovacs & Telegdy 1983; Kovacs et al. 1990; Van de Kar
et al. 1998). Finally, a small microsatellite repeat
sequence in the gene coding for V1aR controls its
density of expression in the ventral pallidum and this
gene region is subject to a number of polymorphisms
that contribute to variability in the strength of mono-
gamous bonding in male prairie voles (Hammock &
Young 2005). The Homo sapiens version of this gene
has similar polymorphisms, which might contribute
to individual differences in human monogamous
pairbonding as well.
The above data suggest that the mammalian
attachment system is distinct from, yet interacts with,
the neural mechanisms for courtship attraction and the
sex drive. This flexible, combinatorial system would
provide individuals of myriad species with the range of
motivations, emotions and behaviours necessary to
pursue their species-specific reproductive strategy.
These data on attachment and romantic love also
lend perspective to another aspect of reproduction,
rejection in love.
9. REJECTION IN LOVE
Romantic love is expressed in many graded forms, but
it has two extremes: love that is returned and love that is
rejected. To understand the range of neural
mechanisms associated with mate choice, Fisher,
Aron, Brown and colleagues used fMRI to study 10
women and 5 men who were still very much in love but
had recently been rejected by their romantic partner
(Fisher et al. 2005a,b). We used the same protocol as
with our happily in-love subjects (Aron et al. 2005).
Rejected participants alternately viewed a photograph
of their abandoning beloved (positive stimulus) and a
photograph of a familiar, emotionally neutral individ-
ual (neutral stimulus), interspersed with a distraction–
attention task.
Preliminary analysis of the positive–neutral contrast
showed significant group effects in the right nucleus
accumbens/ventral putamen/pallidum, lateral orbito-
frontal cortex and anterior insular/operculum cortex
(Fisher et al. 2005a,b). We then compared these data on
rejected lovers with the results from our study of 17
happily in-love individuals (Aron et al. 2005). Rejected
lovers expressed significantly greater activity in the
ventral striatum/putamen/pallidum than did those who
were happily in love (figure 1).
Other studies have shown that the nucleus accum-
bens/ventral pallidum/putamen region where we found
activity becomes more active as an individual chooses a
high-risk investment associated with big gains or big
losses, making it an uncertain gain (Kuhnen &
Knutson 2005), or anticipates a money reward (Zald
et al. 2004); data from rat studies are consistent with
the idea that the nucleus accumbens core is important
for choices for uncertain rewards and delayed
reinforcement (e.g. Cardinal & Howes 2005); activity
in the nucleus accumbens has also been associated with
pairbond formation and maintenance in prairie voles
(Lim et al. 2004). The region of the anterior insula/
operculum cortex where we found activity has been
associated with skin and muscle pain and with anxiety
(Schreckenberger et al. 2005). The region of the lateral
orbitofrontal cortex where we found activity has been
associated with theory of mind (Vollm et al. 2006),
evaluating punishers (Kringelbach & Rolls 2004),
implementing appropriate adjustments in behaviour
(Ridderinkhof et al. 2004), obsessive/compulsive
behaviours (Evans et al. 2004) and with controlling
anger in recently abstinent cocaine-dependent individ-
uals (Goldstein et al. 2005).
These results suggest that brain systems associated
with reward and motivation remain active in recently
romantically rejected men and women, but differ in
their precise location. These preliminary results also
suggest that neural regions associated with risk-taking
for big gains or losses, physical pain, obsessive/com-
pulsive behaviours, ruminating on the intentions and
actions of the rejecter, evaluating options, and emotion
regulation increase in their activity when someone is
rejected by a beloved.
Our study is the second investigation of romantic
rejection. Najib et al. (2004) studied nine women who
were ‘actively grieving’ over a recent romantic break-
up. Our preliminary comparisons uncovered no
commonalities; in fact, in several regions where we
found activations, they found deactivations. Since our
subjects regularly reported anger and hope for reconci-
liation, while subjects in the Najib et al. (2004) study
more regularly reported acceptance, we suspect that
our subjects were in the initial stage of romantic
rejection, the protest phase, while their participants
were largely in the subsequent resignation/despair
phase.
The combined aforementioned data may contribute
understanding to the high cross-cultural rates of
stalking, homicide, suicide and clinical depression
associated with rejection in love (Meloy & Fisher
2005).
–10 –8 –6
Figure 1. Three axial sections through the human brain at
2 mm intervals show a consistent activation difference
between a group happily in love and a group in love but
recently rejected (yellow colour, p!0.01). Those who were
recently rejected show greater activation in the right ventral
putamen–pallidum and accumbens core (side definition is
radiological convention) than those who were happily in love.
These regions have been associated with reward, especially
uncertain large gains and losses in gambling, and uncertain
reinforcement in rats. (Figure data from Aron et al. 2005 and
a preliminary report, Fisher et al. 2005a,b).
2180 H. E. Fisher and others Romantic love
Phil. Trans. R. Soc. B (2006)
10. THE DRIVE TO LOVE
The psychological literature distinguishes between
emotions (affective states of feeling) and motivations
(brain systems oriented around the planning and
pursuit of a specific want or need). Aron has proposed
that romantic love is not primarily an emotion, but a
motivation system designed to enable suitors to build
and maintain an intimate relationship with a preferred
mating partner (Aron & Aron 1991; Aron et al. 1995).
The fMRI and animal experiments we have reviewed
above support Aron’s hypothesis. The VTA is directly
associated with motivation- and goal-oriented
behaviours, as is the caudate nucleus. Moreover, the
caudate nucleus has widespread afferents from all of the
cortex except primary visual areas (Kemp & Powell
1970; Selemon & Goldman-Rakic 1985; Saint-Cyr
et al. 1990; Eblen & Graybiel 1995; Flaherty &
Graybiel 1995) and is organized to integrate diverse
sensory, motor and limbic functions (Brown 1992;
Parthasarathy et al. 1992; Eblen & Graybiel 1995;
Parent & Hazrati 1995; Parent et al. 1995; Brown et al.
1998; Haber 2003). Thus, regions of the caudate
nucleus could effectively integrate the behavioural and
biological actions associated with a complex state, such
as romantic love.
In fact, these findings suggest that romantic love is
a primary motivation system, a fundamental human
mating drive (Fisher 2004). Pfaff (1999) defines a
drive as a neural state that energizes and directs
behaviour to acquire a particular biological need to
survive or reproduce and he reports that all drives are
associated with the activity of dopaminergic pathways
and a few other specific neural systems (as well as
other neural systems specific to each individual drive
state). Romantic love has many characteristics in
common with drives (Fisher 2004). (i) Like drives,
romantic love is tenacious and emotions ebb and flow,
(ii) romantic love is focused on a specific reward and
emotions are associated with a range of phenomena
instead, (iii) romantic love is not associated with a
distinct facial expression and the primary emotions
are all associated with specific facial expressions,
(iv) romantic love is difficult to control and all of the
basic drives are difficult to control, and (v) human
romantic love and mammalian courtship attraction
are associated with dopamine-rich neural regions and
all the basic drives are also associated with dopamin-
ergic pathways. Drives lie along a continuum. Thirst
is almost impossible to control, while the sex drive
can be redirected, even quelled. Romantic love is
evidently stronger than the sex drive because when
one’s sexual overtures are rejected, people do not kill
themselves or someone else. Instead, abandoned
lovers sometimes stalk, commit suicide or homicide
or fall into a clinical depression.
More investigations need to be made to understand
the flexibility, variability and durability of this neural
mechanism for mate choice, romantic love. Data could
be collected on how the neural mechanisms for
romantic love vary in conjunction with specific
traumatic childhood experiences; how specific person-
ality profiles affect the biological expression of romantic
love; how specific diseases, such as schizophrenia and
Parkinson’s disease, and addictions, such as cocaine,
amphetamine and alcohol addiction, facilitate or
inhibit the biological expression of romantic love;
how the constellation of neural correlates associated
with romantic love varies during the course of a long-
term relationship; how the biology of romantic love
varies according to sexual orientation; and how this
brain system varies in cultures with different marital
patterns and in different mammalian species with
diverse reproductive strategies. More research into
the brain mechanisms associated with romantic love
may also help to explain some of the basic principles of
brain lateralization and lend further understanding of
the reward system and its interactions with cognitive
and emotional processes that together produce
complex behaviours.
It might also be valuable to investigate gender
differences in the constellation of neural correlates
associated with early stage (and later stage) romantic
love. In a preliminary study of gender differences, we
did a between-subject analysis of our 10 women and 7
men who were happily in love. Although men and
women were similar in many ways, we did find gender
differences. Men tended to show more activity than
women in a region of the right posterior dorsal insula
that has been correlated with penile turgidity (Arnow
et al. 2002) and male viewing of beautiful faces (Aharon
et al. 2001). Men also showed more activity in regions
associated with the integration of visual stimuli
(Narumoto et al. 2001). Women tended to show more
activity than men in regions associated with attention,
memory and emotion (Gray et al. 2002; Maddock et al.
2003; Velanova et al. 2003).
Extensive cross-cultural data indicate that courting
men respond more strongly than women to visual
signals of youth and beauty (Buss et al. 1990); hence,
we speculate that the above male activation pattern
evolved, in part, to enable ancestral men to respond to
the visual signals of women who could bear them viable
young (Fisher 2004). Cross-cultural data indicate that
women are more attracted than men to potential mates
who offer status and resources (Buss et al. 1990). To
calculate the reproductive value of a man, a woman
must remember the promises and provisioning record
of her potential partner. Thus, we speculate that the
above female activation pattern evolved, in part, to
enable ancestral women to remember male behaviour
patterns and thus make adaptive long-term mate
choices (Fisher 2004). But more research is necessary
to confirm this hypothesis, to establish the cultural
variables that contribute to gender differences and to
find more gender differences in the brain associated
with romantic love.
We expect that human romantic love will be found to
engage a wide range of varying, overlapping and
dynamic brain systems, as would be appropriate of a
multi-faceted phenomenon that has significant social,
reproductive and genetic consequences. Nevertheless,
the primary neural correlates associated with intense,
early-stage romantic love are likely to remain similar
across individuals and cultures, even among species,
because this neural mechanism evolved to direct a
crucial aspect of mammalian reproduction, mate
choice.
Romantic love H. E. Fisher and others 2181
Phil. Trans. R. Soc. B (2006)
REFERENCES
Aharon, I., Etcoff, N., Ariely, D., Chabris, C. F., O’Connor,
E. & Breiter, H. C. 2001 Beautiful faces have variable
reward value: fMRI and behavioral evidence. Neuron 32,
537–551.
Ainsworth, M. D. S., Blehar, M. C., Waters, E. & Wall, S.
1978 Patterns of attachment: a psychological study of the
strange situation. Hillsdale, NJ: Erlbaum.
Andersson, M. 1994 Sexual selection. Princeton, NJ: Prince-
ton University Press.
Appararundaram, S., Huller, J., Lakhlani, S & Jennes L. 2002
Ovariectomy-induced alterations of choline and dopamine
transporter activity in the rat brain. Society for Neuroscience
Abstract Viewer/Itinerary Planner: p.368.20.
Arnow, B. A., Desmond, J. E., Banner, L. L., Glover, G. H.,
Solomon, A., Polan, M. L., Lue, T. F. & Atlas, S. W. 2002
Brain activation and sexual arousal in healthy, hetero-
sexual males. Brain 125, 1014–1023.
Aron, A. & Aron, E. N. 1991 Love and sexuality. In Sexuality
in close relationships (ed. K. McKinney & S. Sprecher),
pp. 25–48. Hillsdale, NJ: Lawrence Erlbaum.
Aron, A., Paris, M. & Aron, E. N. 1995 Falling in love:
prospective studies of self-concept change. J. Pers. Social
Psychol. 69, 1102–1112.
Aron, A., Fisher, H. E., Mashek, D. J., Strong, G., Li, H. F. &
Brown, L. L. 2005 Reward, motivation and emotion
systems associated with early-stage intense romantic love:
an fMRI study. J. Neurophysiol. 94, 327–337.
Aron, A., Fisher, H. E. & Strong, G. 2006 Romantic love. In
The Cambridge handbook of personal relationships (ed.
D. Perlman & A. Vangelisti). Cambridge, MA: Cambridge
University Press.
Ascher, J. A. et al. 1995 Bupropion: a review of its mechanism
of antidepressant activity. J. Clin. Psychiatry 56, 396–402.
Auger, A. P., Meredith, J. M., Snyder, G. L. & Blaustein, J. D.
2001 Oestradiol increases phosphorylation of a dopamine-
and cyclic AMP-regulated phosphoprotein (DARPP-32)
in female rat brain. J. Neuroendocrinol. 13, 761–768.
Bartels, A. & Zeki, S. 2000 The neural basis of romantic love.
Neuroreport 11, 3829–3834.
Bartels, A. & Zeki, S. 2004 The neural correlates of maternal
and romantic love. NeuroImage 21, 1155–1166.
Beach, F. A. 1976 Sexual attractivity, proceptivity, and
receptivity in female mammals. Horm. Behav. 7, 105–138.
Beauregard, M., Levesque, J. & Bourgouin, P. 2001 Neural
correlates of conscious self-regulation of emotion.
J. Neurosci. 21, RC165.
Becker, J. B., Rudick, C. N. & Jenkins, W. J. 2001 The role of
dopamine in the nucleus accumbens and striatum during
sexual behavior in the female rat. J. Neurosci. 21,
3236–3241.
Bell, J. 1995 Notions of love and romance among the Taita of
Kenya. In Romantic passion: a universal experience? (ed.
W. Jankowiak). New York, NY: Columbia University
Press.
Bester-Meredith, J. K., Young, L. J. & Marler, C. A. 1999
Species differences in paternal behavior and aggression in
Peromyscus and their associations with vasopressin immu-
noreactivity and receptors. Horm. Behav. 36, 25–38.
Bowlby, J. 1969. Attachment and loss: attachment , vol. 1. New
York, NY: Basic Books.
Bowlby, J. 1973. Attachment and loss: separation, vol. 2. New
York, NY: Basic Books.
Brown, L. L. 1992 Somatotopic organization in rat striatum:
evidence for a combinational map. Proc. Natl Acad. Sci.
USA 89, 7403–7407.
Brown, L. L., Smith, D. M. & Goldbloom, L. M. 1998
Organizing principles of cortical integration in the rat
neostriatum: corticostriate map of the body surface is an
ordered lattice of curved laminae and radial points.
J. Comp. Neurol. 392, 468–488.
Buffum, J., Moser, C. & Smith, D. 1988 Street drugs and
sexual function. In Handbook of sexology, vol. 6 (ed.
J. M. A. Sitsen) The pharmacolog y and endocrinology of
sexual function. New York, NY: Elsevier Science
Publishers.
Buss, D. M. et al. 1990 International preferences in selecting
mates: a study of 37 societies. J. Cross Cult. Psychol. 21,
5–47.
Cardinal, R. N. & Howes, N. J. 2005 Effects of lesions of the
accumbens core on choice between small uncertain
rewards in rats. BMC Neurosci. 6, 37–56.
Carter, C. S. 1992 Oxytocin and sexual behavior. Neurosci.
Biobehav. Rev. 1, 131–144.
Carter, C. S., DeVries, A., Taymans, S. E., Roberts, R. L.,
Williams, J. R. & Getz, L. L. 1997 Peptides steroids, and
pair bonding. In The integrative neurobiology of affiliation,
vol. 807 (ed. C. S. Carter, I. I. Lederhendler & B.
Kirkpatrick), pp. 260–272. Annals of the New York
Academy of Sciences, New York, NY: The New York
Academy of Sciences.
Clayton, A. H. et al. 2000 Bupropion as an antidote to SSRI-
induced sexual dysfunction. Poster presented at the New
Clinical Drug Evaluation Unit Program (NCDEU), Boca
Raton, FL.
Clayton, A. H., Pradko, J. F., Croft, H. A., Montano, C. B.,
Leadbetter, R. A., Bolden-Watson, C., Bass, K. I.,
Donahue, R. M., Jamerson, B. D. & Metz, A. 2002
Prevalence of sexual dysfunction among newer anti-
depressants. J. Clin. Psychiatry 63, 357–366.
Coleman, C. C., Cunningham, L. A., Foster, V. J., Batey,
S. R., Donahue, R. M. J., Houser, T. L. & Ascher, J. A.
1999 Sexual dysfunction associated with the treatment of
depression: a placebo-controlled comparison of bupro-
prion sustained release and sertraline treatment. Ann.
Clin. Psychiatry 11, 205–215.
Coull, J. 1998 Neural correlates of attention and arousal
Insights from electrophysiology, functional neuroimaging
and psychopharmacology. Prog. Neurobiol. 55, 343–361.
Creutz, L. M. & Kritzer, M. F. 2002 Estrogen receptor-
beta immunoreactivity in the midbrain of adult rats:
regional, subregional, and cellular localization in the
A10, A9, and A8 dopamine cell groups. J. Comp. Neurol.
446, 288–300.
Cronbach, L. J. 1951 Coefficient alpha and the internal
structure of tests. Psychometrika 16, 297–334.
Darwin, C. 1871/n.d. The descent of man and selection
in relation to sex. New York, NY: The Modern Library/
Random House.
Davidson, R. J. 1994 Complexities in the search for emotion-
specific physiology. In The nature of emotion: fundamental
questions (ed. P. Ekman & R. J. Davidson). New York, NY:
Oxford University Press.
Delgado, M. R., Nystrom, L. E., Fissell, C., Noll, D. C. &
Fiez, J. A. 2000 Tracking the hemodynamic responses to
reward and punishment in the striatum. J. Neurophysiol.
84, 3072–3077.
Dixson, A. F. 1998 Primate sexuality. Oxford, UK: Oxford
University Press.
Dluzen, D. E., Ramirez, V. D., Carter, C. S. & Getz, L. L.
1981 Male vole urine changes luteinizing hormone-
releasing hormone and norepinephrine in female olfactory
bulb. Science 212, 573–575.
Eblen, F. & Graybiel, A. M. 1995 Highly restricted origin of
prefrontal cortical inputs to striosomes in the macaque
monkey. J. Neurosci. 15, 5999–6013.
2182 H. E. Fisher and others Romantic love
Phil. Trans. R. Soc. B (2006)
Edwards, J. N. & Booth, A. 1994 Sexuality, marriage, and
well-being: the middle years. In Sexuality across the life
course (ed. A. S. Rossi). Chicago, IL: University of Chicago
Press.
Elliott, R., Newman, J. L., Longe, O. A. & Deakin, J. W. F.
2003 Differential response patterns in the striatum and
orbitofrontal cortex to financial reward in humans: a
parametric functional magnetic resonance imaging study.
J. Neurosci. 23, 303–307.
Etgen, A. & Morales, J. C. 2002 Somatosensory stimuli
evoke norepinephrine release in the anterior ventro-
medial hypothalamus of sexually receptive female rats.
J. Neuroendocrinol. 14, 213–218.
Etgen, A. M., Chu, H. P., Fiber, J. M., Karkanias, G. B. &
Morales, J. M. 1999 Hormonal integration of neurochem-
ical and sensory signals governing female reproductive
behavior. Behav. Brain Res. 105, 93–103.
Evans, D. W., Lewis, M. D. & Iobst, E. 2004 The role of the
orbitofrontal cortex in normally developing compulsive-
like behaviors and obsessive–compulsive disorder. Brain
Cogn. 55, 220–234.
Fabre-Nys, C. 1997 Male faces and odors evoke differential
patterns of neurochemical release in the mediobasal
hypothalamus of the ewe during estrus: an insight into
sexual motivation. Eur. J. Neurosci. 9, 1666–1677.
Fabre-Nys, C. 1998 Steroid control of monoamines in
relation to sexual behaviour. Rev. Reprod. 3, 31–41.
Ferrari, F. & Giuliani, D. 1995 Sexual attraction and
copulation in male rats: effects of the dopamine agonist
SND 919. Pharmacol. Biochem. Behav. 50, 29–34.
Fiorino, D. F., Coury, A. & Phillips, A. G. 1997 Dynamic
changes in nucleus accumbens dopamine efflux during the
Coolidge effect in male rats. J. Neurosci. 17, 4849–4855.
Fisher, H. E. 1992 Anatomy of love: the natural history of
monogamy, adultery and divorce. New York, NY: WW
Norton.
Fisher, H. 1998 Lust, attraction, and attachment in
mammalian reproduction. Human Nature 9, 23–52.
Fisher, H. 2004 Why we love: the nature and chemistry of
romantic love. New York, NY: Henry Holt.
Fisher, H., Aron, A., Mashek, D., Strong, G., Li, H. &
Brown, L. L. 2002a The neural mechanisms of mate
choice: a hypothesis. Neuroendocrinol. Lett. 23(Suppl. 4),
92–97.
Fisher, H., Aron, A., Mashek, D., Strong, G., Li, H. &
Brown, L. L. 2002b Defining the brain systems of lust,
romantic attraction and attachment. Arch. Sexual Behav.
31, 413–419.
Fisher, H., Aron, A., Mashek, D., Strong, G., Li, H. &
Brown, L. L. 2005a Motivation and emotion systems
associaed with romantic love following rejection: an fMRI
study. Program no. 660.7. Abstract Viewer/Itinerary
Planner. Washington, DC: Society for Neuroscience,
Online.
Fisher, H., Aron, A. & Brown, L. L. 2005b Romantic love: an
fMRI study of a neural mechanism for mate choice.
J. Comp. Neurol. 493, 58–62.
Fisher, H. E. & Thomson, J. A. In press. Lust, attraction,
attachment: the neural mechanisms of mate choice and
how antidepressants jeopardize romantic love, attachment
and one’s genetic future. In Evolutionary cognitive neuro-
science. Steven Platek (ed.). Cambridge, MA: MIT Press.
Flaherty, A. W. & Graybiel, A. M. 1995 Motor and
somatosensory corticostriatal projection magnifications
in the squirrel monkey. J. Neurophysiol. 74, 2638–2648.
Fraley, G. S. 2002 Immunolesion of hindbrain catechol-
aminergic projections to the medial hypothalamus attenu-
ates penile reflexive erections and alters hypothalamic
peptide mRNA. J. Neuroendocrinol. 14, 345–348.
Fraley, R. C. & Shaver, P. R. 2000 Adult romantic
attachment: theoretical developments, emerging contro-
versies and unanswered questions. Rev. Gen. Psychol. 4,
132–154.
Galfi, M., Janaky, T., Toth, R., Prohaszka, G., Juhasz, A.,
Varga, C. & Laszlo, F. A. 2001 Effects of dopamine and
dopamine-active compounds on oxytocin and vasopressin
production in rat neurohypophyseal tissue cultures. Regul.
Pept. 98, 49–54.
Gerfen, C. R., Herkenham, M. & Thibault, J. 1987 The
neostriatal mosaic: II. Patch- and matrix-directed meso-
striatal dopaminergic and non-dopaminergic systems.
J. Neurosci. 7, 3915–3934.
Gingrich, B., Liu, Y., Cascio, C. Z. & Insel, T. R. 2000
Dopamine D2 receptors in the nucleus accumbens are
important for social attachment in female prairie voles
(Microtus ochrogaster). Behav. Neurosci. 114, 173–183.
Ginsberg, S. D., Hof, P. R., Young, W. G. & Morrison, J. H.
1994 Noradrenergic innervation of vasopressin- and
oxytocin-containing neurons in the hypothalamic para-
ventricular nucleus of the macaque monkey: quantitative
analysis using double-label immunohistochemistry and
confocal laser microscopy. J. Comp. Neurol. 341, 476–491.
Gladikas, B. M. 1995 Reflections of Eden: my years with the
Orangutans of Borneo. New York, NY: Little Brown and
Company.
Goldstein, R. Z., Alai-Klein, N., Leskovjan, A. C., Fowler,
J. S., Wang, G. J., Gur, R. C., Hitzemann, R. & Volkow,
N. D. 2005 Anger and depression in cocaine addiction:
association with the orbitofrontal cortex. Psychiatry Res.
138, 13–22.
Gonzaga, G. C., Keltner, D., Londahl, E. A. & Smith, M. D.
2001 Love and the commitment problem in romantic
relations and friendship. J. Pers. Soc. Psychol. 81, 247–262.
Goodall, J. 1986 The Chimpanzees of Gombe: patterns of
behavior. Cambridge, MA: The Belknap Press of Harvard
University Press.
Gray, J. R., Braver, T. S. & Raichle, M. E. 2002 Integration of
emotion and cognition in the lateral prefrontal cortex.
Proc. Natl Acad. Sci. USA 99, 4115–4120.
Griffin, M. G. & Taylor, G. T. 1995 Norepinephrine
modulation of social memory: evidence for a time-
dependent functional recovery of behavior. Behav.
Neurosci. 109, 466–473.
Haber, S. N. 2003 The primate basal ganglia: parallel and
integrative networks. J. Chem. Neuroanat. 26, 317–330.
Hammock, E. A. D. & Young, L. J. 2005 Microsatellite
instability generates diversity in brain and sociobehavioral
traits. Science 308, 1630–1634.
Harris, C. R. & Christenfeld, N. 1996 Gender, jealousy, and
reason. Psychol. Sci. 7, 364–366.
Hatfield, E. 1988 Passionate and companionate love. In The
psychology of love (ed. R. J. Sternberg & M. S. L. Barnes).
New Haven, CT: Yale University Press.
Hatfield, E. & Sprecher, S. 1986 Measuring passionate love
in intimate relations. J. Adolesc. 9, 383–410.
Hatfield, E., Schmitz, E., Cornelius, J. & Rapson, R. L. 1988
Passionate love: how early does it begin? J. Psychol. Hum.
Sex. 1, 35–51.
Hazan, C. & Diamond, L. M. 2000 The place of attachment
in human mating. Rev. Gen. Psychol. 4, 186–204.
Hazan, C. & Shaver, P. R. 1987 Romantic love conceptu-
alized as an attachment process. J. Pers. Social Psychol. 52,
511–524.
Heaton, J. P. 2000 Central neuropharmacological agents and
mechanisms in erectile dysfunction: the role of dopamine.
Neurosci. Biobehav. Rev. 24, 561–569.
Herbert, J. 1996 Sexuality, stress and the chemical
architecture of the brain. Annu. Rev. Sex Res. 7, 1–44.
Romantic love H. E. Fisher and others 2183
Phil. Trans. R. Soc. B (2006)
Hull, E. M., Du, J., Lorrain, D. S. & Matuszewich, L. 1995
Extracelular dopamine in the medial preoptic area:
implicatons for sexual motivation and hormonal control
of copulation. J. Neurosci. 15, 7465–7471.
Hull, E. M., Du, J., Lorrain, D. S. & Matuszewick, L. 1997
Testosterone, preoptic dopamine, and copulation in male
rats. Brain Res. Bull. 44, 327–333.
Hull, E. M., Lorrain, D. S., Du, J., Matuszewick, L., Lumley,
L. A., Putnam, S. K. & Moses, J. 1999 Hormone–
neurotransmitter interactions in the control of sexual
behavior. Behav. Brain Res. 105, 105–116.
Hull, E., Meisel, R. & Sachs, B. D. 2002 Male sexual
behavior. In Hormones, brain, and behavior (ed. D. W. Pfaff,
A. P. Arnold, A. M. Etgen, S. E. Fahrbach & R. T. Rubin),
pp. 1–139. Boston, MA: Academic Press.
Hutchison, J. B. & Hutchison, R. E. 1983 Hormonal
mechanisms of mate choice in birds. In Mate choice (ed.
P. Bateson), pp. 389–405. Cambridge: Cambridge
University Press.
Jankowiak, W. R. & Fischer, E. F. 1992 A cross-cultural
perspective on romantic love. Ethnology 31, 149.
Karama, S., Lecours, A. R., Leroux, J. M., Bourgouin, P.,
Beaudoin, G., Joubert, S. & Beauregard, M. 2002 Areas of
brain activation in males and females during viewing of
erotic film excerpts. Hum. Brain Mapp. 16, 1–13.
Kawashima, S. & Takagi, K. 1994 Role of sex steroids on the
survival, neuritic outgrowth of neurons, and dopamine
neurons in cultured preoptic area and hypothalamus.
Horm. Behav. 28, 305–312.
Kemp, J. M. & Powell, T. P. 1970 The cortico-striate
projection in the monkey. Brain 93, 525–546.
Kendrick, K. M. 2000 Oxytocin, motherhood and bonding.
Exp. Physiol. 85S, 111S–124S.
Kendrick, K. M. & Dixson, A. F. 1985 Luteinizing hormone
releasing hormone enhances proceptivity in a primate.
Neuroendocrinology 41, 449–453.
Kendrick, K. M. & Dixson, A. F. 1986 Anteromedial
hypothalamic lesions block proceptivity but not receptivity
in the female common marmoset (Callithrix jacchus). Brain
Res. 375, 221–229.
Kendrick, K. M., Keverne, E. B., Hinton, M. R. & Goode,
J. A. 1992 Oxytocin, amino acid and monoamine release
in the region of the medial preoptic area and bed nucleus
of the stria terminalis of the sheep during parturition and
suckling. Brain Res. 569, 199–209.
Kovacs, G. & Telegdy, G. 1983 Effects of oxytocin, des-
glycinamide-oxytocin and anti-oxytocin serum on the
alpha-MPT-induced disappearance of catecholamines in
the rat brain. Brain Res. 268, 307–314.
Kovacs, G. L., Sarnyai, Z., Barbarczi, E., Szabo, G. &
Telegdy, G. 1990 The role of oxytocin-dopamine
interactions in cocaine-induced locomotor hyperactivity.
Neuropharmacology 29, 365–368.
Kringelbach, M. L. & Rolls, E. T. 2004 The functional
neuroanatomy of the human orbitofrontal cortex: evi-
dence from neuroimaging and neuropsychology. Prog.
Neurobiol. 72, 341–372.
Kuhnen, C. M. & Knutson, B. 2005 The neural basis of
financial risk taking. Neuron 47, 763–770.
Lauwereyns, J., Takikawa, Y., Kawagoe, R., Kobayashi,
S., Koizumi, M., Coe, B., Sakagami, M. & Hikosaka,
O. 2002 Feature-based anticipation of cues that
predict reward in monkey caudate nucleus. Neuron
33, 463–473.
Lavin, A., Nogueira, L., Lapish, C. C., Wightman, R. M.,
Phillips, P. E. M. & Seamans, J. K. 2005 Mesocortical
dopamine neurons operate in distinct temporal domains
using multimodal signaling. J. Neurosci. 25, 5013–5023.
Legault, M. & Wise, R. A. 1999 Injections of N-methyl-
D-asparate into the ventral hippocampus increase extra-
ceullular dopamine in the ventral tegmental area and
nucleus accumbens. Synapse 31, 241–249.
Liebowitz, M. R. 1983 The chemistry of love. Boston, MA:
Little Brown.
Lim, M. M. & Young, L. J. 2004 Vasopressin-dependent
neural circuits underlying pair bond formation in the
monogamous prairie vole. Neuroscience 128, 35–45.
Lim, M. M., Murphy, A. Z. & Young, A. J. 2004 Ventral
striatopallidal oxytocin and vasopressin V1a receptors in
the monogamous prairie vole (Microtus ochrogaster).
J. Comp. Neurol. 468, 555–570.
Liu, Y.-C, Sachs, B. D. & Salamone, J. D. 1998 Sexual
behavior in male rats after radiofrequency or dopamine-
depleting lesions in nucleus accumbens. Pharmacol.
Biochem. Behav. 60, 585–592.
Maddock, R. J., Garrett, A. S. & Buonocore, M. H. 2003
Posterior cingulate cortex activation by emotional words:
fMRI evidence from a valence decision task. Hum. Brain
Mapp. 18, 30–41.
Marazziti, D., Akiskal, H. S., Rossi, A. & Cassano, G. B. 1999
Alteration of the platelet serotonin transporter in romantic
love. Psychol. Med. 29, 741–745.
Martin-Soelch, C., Leenders, K. L., Chevalley, A. F.,
Missimer, J., Kunig, G., Magyar, S., Mino, A. &
Schultz, W. 2001 Reward mechanisms in the brain and
their role in dependence: evidence from neurophysiologi-
cal and neuroimaging studies. Brain Res. Rev. 36,
139–149.
Mashek, D., Aron, A. & Fisher, H. E. 2000 Identifying,
evoking, and measuring intense feelings of romantic love.
Rep. Res. Social Psychol. 24, 48–55.
McCullough, D. 2001 John Adams. New York, NY: Simon
and Schuster.
Meloy, J. R. & Fisher, H. 2005 Some thoughts on the
neurobiology of stalking. Forensic Sci. 50, 1472–1480.
Miller, G. 2000 The mating mind: how sexual choice shaped the
evolution of human nature. New York, NY: Doubleday.
Moles, A., Kieffer, B. L. & D’Amato, F. R. 2004 Deficit in
attachment behavior in mice lacking the u-opioid receptor
gene. Science 304, 1983–1985.
Montague, P. R., McClure, S. M., Baldwin, R. P., Phillips,
P. E., Budygin, E. A., Stuber, G. D., Kilpatrick, M. R. &
Wightman, R. M. 2004 Dynamic gain control of
dopamine delivery in freely moving animals. J. Neurosci.
24, 1754–1759.
Montejo, A. L., Llorca, G., Izquierdo, J. A. & Rico-
Vallademoros, F. 2001 Incidence of sexual dysfunction
associated with antidepressant agents: a prospective
multicenter study of 1022 outpatients. J. Clin. Psychiatry
62, 1020.
Najib, A., Lorberbaum, J. P., Kose, S., Bohning, D. E. &
George, M. S. 2004 Regional brain activity in women
grieving a romantic relationship breakup. Am. J. Psychiatry
161, 2245–2256.
Narumoto, J., Okada, T., Sadato, N., Fukui, K. & Yonekura,
Y. 2001 Attention to emotion modulates fMRI activity in
human right superior temporal sulcus. Brain Res. Cogn. 12,
225–231.
Nyborg, H. 1994 Hormones, sex and society. Westport, CT:
Praeger.
Oades, R. D. & Halliday, G. M. 1987 Ventral tegmental
(A10) system: neurobiology. 1. Anatomy and connectivity.
Brain Res. 434, 117–165.
O’Doherty, J. P., Deichmann, R., Critchley, H. D. & Dolan,
R. J. 2002 Neural responses during anticipation of a
primary taste reward. Neuron 33, 815–826.
2184 H. E. Fisher and others Romantic love
Phil. Trans. R. Soc. B (2006)
Panksepp, J. 1998 Affective neuroscience: the foundations of
human and animal emotions. New York, NY: Oxford
University Press.
Parent, A. & Hazrati, L. N. 1995 Functional anatomy of
the basal ganglia. I. The cortico-basal ganglia-thalamo-
cortical loop. Brain Res. Brain Res. Rev. 20, 91–127.
Parent, A., Cote, Y. & Lavoie, B. 1995 Anatomy of primate
basal ganglia. Prog. Neurobiol. 46, 131–197.
Parthasarathy, H. B., Schall, J. D. & Graybiel, A. M. 1992
Distributed but convergent ordering of corticostriatal
projections: analysis of the frontal eye field and the
supplementary eye field in the macaque monkey.
J. Neurosci. 12, 4468–4488.
Pfaff, D. W. 1999 DRIVE: neurobiological and molecular
mechanisms of sexual motivation. Cambridge, MA: The
MIT Press.
Pfaff, D. W. 2005 Brain arousal and information theory.
Cambridge, MA: Harvard University Press.
Pfaff, D., Frohlich, J. & Morgan, M. 2002 Hormonal and
genetic influences on arousal sexual and otherwise.
Trends Neurosci. 25, 45–50.
Pitkow, L. J., Sharer, C. A., Ren, X., Insel, T. R., Terwilliger,
E. F. & Young, L. J. 2001 Facilitation of affiliation and
pair-bond formation by vasopressin receptor gene transfer
into the ventral forebrain of a monogamous vole.
J. Neurosci. 21, 7392–7396.
Posner, M. & Petersen, S. 1990 The attention system of the
human brain. Annu. Rev. Neurosci. 13, 25–42.
Ridderinkhof, K. R., van den Wildenberg, W. P.,
Segalowitz, S. J. & Carter, C. S. 2004 Neurocognitive
mechanisms of cognitive control: the role of prefrontal
cortex in action selection, response inhibition, per-
formance monitoring, and reward-based learning. Brain
Cogn. 56, 129–140.
Robbins, T., Granon, S., Muir, J., Durantou, P., Harrison, A.
& Everitt, B. 1998 Neural systems underlying arousal and
attention: implications for drug abuse. Ann. NY Acad. Sci.
846, 222–237.
Robinson, D. L., Heien, M. L. & Wightman, R. M. 2002
Frequency of dopamine concentration transients increases
in dorsal and ventral striatum of male rats during intro-
duction of conspecifics. J. Neurosci. 22, 10 477–10 486.
Rosen, R. C., Lane, R. M. & Menza, M. 1999 Effects of
SSRIs on sexual function: a critical review. J. Clin.
Psycopharmacol. 19, 67–85.
Saint-Cyr, J. A., Ungerleider, L. G. & Desimone, R. 1990
Organization of visual cortical inputs to the striatum and
subsequent outputs to the pallido-nigral complex in the
monkey. J. Comp. Neurol. 298, 129–156.
Schreckenberger, M., Siessmeier, T., Viertmann, A.,
Landvogt, C., Buchholz, H. G., Rolke, R., Treede, R. D.
& Bartenstein, F. 2005 The unpleasantness of tonic pain is
encoded by the insular cortex. Neurology 64, 1175–1183.
Schultz, W. 2000 Multiple reward signals in the brain. Nat.
Rev. Neurosci. 1, 199–207.
Schwarzberg, H., Kovacs, G. L., Szabo, G. & Telegdy, G.
1981 Intraventricular administration of vasopressin and
oxytocin affects the steady-state levels of serotonin,
dopamine and norepinephrine in rat brain. Endocrinol.
Exp. 15, 75–80.
Segraves, R. T., Croft, H., Kavoussi, R., Ascher, J. A., Batey,
S. R., Foster, V. J., Bolden-Watson, C. & Metz, A. 2001
Bupropion sustained release (SR) for treatment of
hypoactive sexual desire disorder (HSDD) in nonde-
pressed women. J. Sex Marital Ther. 27, 303–316.
Selemon, L. D. & Goldman-Rakic, P. S. 1985 Longitudinal
topography and interdigitation of corticostriatal pro-
jections in the rhesus monkey. J. Neurosci. 5, 776–794.
Seybold, V. S., Miller, J. W. & Lewis, P. R. 1978 Investigation
of a dopaminergic mechanism for regulating oxytocin
release. J. Pharmacol. Exp. Ther. 207, 605–610.
Shaver, P., Schwartz, J., Kirson, D. & O’Connor, C. 1987
Emotion knowledge: further exploration of a prototype
approach. J. Pers. Soc. Psychol. 52, 1061–1086.
Sherwin, B. B. 1994 Sex hormones and psychological
functioning in postmenopausal women. Exp. Gerontol.
29, 423–430.
Shostak, M. 1981 Nisa: the life and words of a !Kung woman.
Cambridge, MA: Harvard University Press.
Szezypka, M. S., Zhou, Q. Y. & Palmiter, R. D. 1998
Dopamine-stimulated sexual behavior is testosterone
dependent in mice. Behav. Neurosci. 112, 1229–1235.
Tennov, D. 1979 Love and limerence: the experience of being in
love. New York, NY: Stein and Day.
Van Bockstaele, E. J., Pieribone, V. A. & Aston-Jones, G.
1989 Diverse afferents converge on the nucleus para-
gigantocellularis in the rat ventrolateral medulla: retro-
grade and anterograde tracing studies. J. Comp. Neurol.
290, 561–584.
Van de Kar, L. D., Levy, A. D., Li, Q. & Brownfield, M. S.
1998 A comparison of the oxytocin and vasopressin
responses to the 5-HT1A agonist and potential anxiolytic
drug alnespirone (S-20499). Pharmacol. Biochem. Behav.
60, 677–683.
Van Goozen, S., Wiegant, V. M., Endert, E., Helmond, F. A.
& Van de Poll, N. E. 1997 Psychoendocrinological
assessment of the menstrual cycle: the relationship
between hormones, sexuality, and mood. Arch. Sex.
Behav. 26, 359–382.
Velanova, K., Jacoby, L. L., Wheeler, M. E., McAvoy, M. P.,
Petersen, S. E. & Buckner, R. L. 2003 Functional-
anatomic correlates of sustained and transient processing
components engaged during controlled retrieval.
J. Neurosci. 23, 8460–8470.
Vizi, E. S. & Volbekas, V. 1980 Inhibition by dopamine of
oxytocin release from isolated posterior lobe of the
hypophysis of the rat: disinhibitory effect of beta-
endorphin/enkephalin. Neuroendocrinology 31, 46–52.
Vollm, B. A., Taylor, A. N., Richardson, P., Corcoran, R.,
Stirling, J., McKie, S., Deakin, J. F. & Elliott, R. 2006
Neuronal correlates of theory of mind and empathy: a
functional magnetic resonance imaging study in a
nonverbal task. Neuroimage 29, 90–98.
Walker, P. W., Cole, J. O. & Gardner, E. A. 1993
Improvement in fluoxetine-associated sexual dysfunction
in patients switched to bupropion. J. Clin. Psychiatry 54,
459–465.
Wang, Z. X., Ferris, C. F. & De Vries, G. J. 1994 The role of
septal vasopressin innervation in paternal behavior in
prairie voles (Microtus ochrogaster). Proc. Natl Acad. Sci.
USA 91, 400–404.
Wang, Z., Toloczko, D., Young, L. J., Moody, K., Newman,
J. D. & Insel, T. R. 1997 Vasopressin in the forebrain of
common marmosets (Calithrix jacchus): studies with in situ
hybridization, immunocytochemistry and receptor auto-
radiography. Brain Res. 768, 147–156.
Wang, Z., Yu, G., Cascio, C., Liu, Y., Gingrich, B. & Insel,
T. R. 1999 Dopamine D2 receptor-mediated regulation of
partner preferences in female prairie voles (Microtus
ochrogaster): a mechanism for pair bonding? Behav.
Neurosci. 113, 602–611.
Wenkstern, D., Pfaus, J. G. & Fibiger, H. C. 1993 Dopamine
transmission increases in the nucleus accumbens of male
rats during their first exposure to sexually receptive female
rats. Brain Res. 618, 41–46.
Wersinger, S. R. & Rissman, E. F. 2000 Dopamine activates
masculine sexual behavior independent of the estrogen
receptor alpha. J. Neurosci. 20, 4248–4254.
Romantic love H. E. Fisher and others 2185
Phil. Trans. R. Soc. B (2006)
West, C. H. K., Clancy, A. N. & Michael, R. P. 1992
Enhanced responses of nucleus accumbens neurons in
male rats to novel odors associated with sexually receptive
females. Brain Res. 585, 49–55.
Williams, S. M. & Goldman-Rakic, P. S. 1998 Widespread
origin of the primate mesofrontal dopamine system. Cereb.
Cortex 8, 321–345.
Williams, J. R., Insel, T. R., Harbaugh, C. R. & Carter, C. S.
1994 Oxytocin administered centrally facilitates formation
of a partner preference in female prairie voles (Microtus
ochrogaster). J. Neuroendocrinol. 6, 247–250.
Winslow, J. T., Hastings, N., Carter, C. S., Harbaugh, C. R. &
Insel, T. R. 1993 A role for central vasopressin in pair
bonding in monogamous prairie voles. Nature 365, 545–548.
Wise, R. A. 1996 Neurobiology of addiction. Curr. Opin.
Neurobiol. 6, 243–251.
Young, L. J. 1999 Oxytocin and vasopressin receptors and
species-typical social behaviors. Horm. Behav. 36,
212–221.
Young, L. J., Winslow, J. T., Nilsen, R. & Insel, T. R. 1997
Species differences in V1a receptor gene expression in
monogamous and nonmonogamous voles: behavioral
consequences. Behav. Neurosci. 111 , 599–605.
Young, L. J., Wang, Z. & Insel, T. R. 1998 Neuroendocrine
bases of monogamy. Trends Neurosci. 21, 71–75.
Young, L. J., Lim, M. M., Gingrich, B. & Insel, T. R. 2001
Cellular mechanisms of social attachment. Horm. Behav.
40, 133–138.
Zald, D. H., Boileau, I., El-Dearedy, W., Gunn, R.,
McGlone, F., Dichter, G. S. & Dagher, A. 2004
Dopamine transmission in the human striatum during
monetary reward tasks. J. Neurosci. 24, 4105–4112.
2186 H. E. Fisher and others Romantic love
Phil. Trans. R. Soc. B (2006)
... "Capable" not only means physically able to perform a reproductive action (as determined by the specific simulation), but also requires the agents to be motivated towards that action (i.e., to have a sex drive). In biological contexts, bodily glands release hormones that modulate reproductive motivation in the brain (Wise, 1987;Fisher et al., 2006;Cummings and Becker, 2012). A bodily origin of motivations in natural agents is interesting to notice in our context, since it implies motivation evolves with the body. ...
... Evolution is undoubtedly geared towards reproduction in humans also, yet there is certainly more to human life than simply passing on genes, and human reproduction is also moulded by cultural influences (Henrich and McElreath, 2003). Hence, both cultural and biological drivers affect human reproductive fitness at different steps in the reproductive cycle, from the socalled sexual selection of detecting and seducing a mate (Fisher et al., 2006;Bode and Kushnick, 2021) to several pre-and postzygotic arenas for selection. ...
Article
Full-text available
Humans are shaped by evolution through natural selection, as are all species. While evolution is central to all biological processes, the key stage for competition and selection is reproduction, which encompasses various events from courtship and mating to fertilization and pregnancy. In humans, IVF is used to aid the intrinsically inefficient reproduction by coitus, and in several countries, the proportion of children born after IVF is increasing. While IVF is an enabling technology for infertile patients, it also circumvents reproductive barriers and changes selection pressures. This grand theme review describes the systematic differences between IVF and coitus in selection pressures on reproducing cells, individuals and populations. At the cellular unit of selection, for example, IVF favours different traits in spermatozoa (fast swimmers over short distances) than coitus does (forward mobility over longer distances). Similarly, a male with low sperm quality and a female who decides to delay her first birth to an advanced age, can both increase their reproductive fitness by IVF compared to if reproduction by coitus is their only option. In as much as delayed reproduction is a cultural trait, IVF thus enables cultural practices that may in their turn affect human evolution. A main point in this review is to discuss the interactive effects of biological and V C The Author(s) cultural traits in the context of IVF, and how they act in concert as drivers towards increased demand for IVF. It is not the aim of this review to argue against IVF, which no doubt is a major medical advancement, but rather to examine IVF and human evolution from a broad perspective, including potential longer-term impacts. Since IVF is a young technology, the empirical data indicative of evolutionary effects of IVF in humans are sparse. In general, we argue that IVF facilitates the redirection of resources away from reproduction in humans, since reproduction by IVF bypasses some of the resource-demanding processes that reproduction by coitus entails. Hence, IVF sets the evolutionary stage for a human species increasingly reliant on, and adapted to, technological means of reproduction.
... Evolution is undoubtedly geared towards reproduction in humans also, yet there is certainly more to human life than simply passing on genes, and human reproduction is also moulded by cultural influences (Henrich and McElreath, 2003). Hence, both cultural and biological drivers affect human reproductive fitness at different steps in the reproductive cycle, from the socalled sexual selection of detecting and seducing a mate (Fisher et al., 2006;Bode and Kushnick, 2021) to several pre-and postzygotic arenas for selection. ...
Article
Full-text available
Humans are shaped by evolution through natural selection, as are all species. While evolution is central to all biological processes, the key stage for competition and selection is reproduction, which encompasses various events from courtship and mating to fertilization and pregnancy. In humans, IVF is used to aid the intrinsically inefficient reproduction by coitus, and in several countries, the proportion of children born after IVF is increasing. While IVF is an enabling technology for infertile patients, it also circumvents reproductive barriers and changes selection pressures. This grand theme review describes the systematic differences between IVF and coitus in selection pressures on reproducing cells, individuals and populations. At the cellular unit of selection, for example, IVF favours different traits in spermatozoa (fast swimmers over short distances) than coitus does (forward mobility over longer distances). Similarly, a male with low sperm quality and a female who decides to delay her first birth to an advanced age, can both increase their reproductive fitness by IVF compared to if reproduction by coitus is their only option. In as much as delayed reproduction is a cultural trait, IVF thus enables cultural practices that may in their turn affect human evolution. A main point in this review is to discuss the interactive effects of biological and V C The Author(s) cultural traits in the context of IVF, and how they act in concert as drivers towards increased demand for IVF. It is not the aim of this review to argue against IVF, which no doubt is a major medical advancement, but rather to examine IVF and human evolution from a broad perspective, including potential longer-term impacts. Since IVF is a young technology, the empirical data indicative of evolutionary effects of IVF in humans are sparse. In general, we argue that IVF facilitates the redirection of resources away from reproduction in humans, since reproduction by IVF bypasses some of the resource-demanding processes that reproduction by coitus entails. Hence, IVF sets the evolutionary stage for a human species increasingly reliant on, and adapted to, technological means of reproduction.
... Similarly, in a survey of more than 5000 internet respondents including university students, Taylor and Bryant (2007) found that romantic breakups were associated with more extreme physical and emotional distress including exaggerated attempts to re-establish the relationship, angry, vengeful behaviour and attempts to kill oneself, drugs and alcohol use. Fisher, Aron and Brown (2006) also found that young women who are still very much in love but had been rejected by their romantic partner alternatively always view a photograph of their abandoning loved one. ...
Article
Full-text available
The study examined social variables and suicidal behaviour tendency among university students in Akwa Ibom State. Two purposes, research questions and hypotheses apiece were formulated to guide the study. The researchers adopted the descriptive survey design. The population of the study comprised all the 5,905 year three undergraduates in the 2 public universities in the state. A sample size of 590 undergraduates was selected through multi-staged sampling procedure. Also, systematic random sampling technique was used to select 10 faculties from the two universities, hence, 59 respondents from each of the sampled faculties were selected using hat and draw method. The researchers self-structured and validated instrument titled "Social Variables and Suicidal Behaviour Tendency among University Students Questionnaire" (SVSBTUSQ) was used for data collection. In order to establish the reliability of the instrument, Cronbach Alpha statistics was applied for test of internal consistency which yielded the reliability coefficient of .87 and .76. Mean and standard deviation were used in answering the research questions, while Independent t-test was used for testing of hypotheses. Findings of the study showed that suicidal behaviour tendency among university students significantly differ based on estrangement in relationship and family emotionally climate. Conclusion was drawn from the findings and the study recommended among other things that: parents should always maintain emotionally stable and well-adjusted homes where students' i Correspondence: email inyorere@yahoo.com,
... Relatively few studies have assessed whether the neural processes that support longer-term bonding and attachment differ between samesex and opposite-sex contexts (Diamond, 2004;Fisher et al., 2006Fisher et al., , 2002. Diamond (2003) proposed that few differences should be expected, based on the premise that human pair bonding likely co-opted the already evolved circuits supporting infant-to-caregiver attachment, which operate independently of the caregiver's sex. ...
Article
Full-text available
Pair bonding is a psychological construct that we attempt to operationalize via behavioral and physiological measurements. Yet, pair bonding has been both defined differently in various taxonomic groups as well as used loosely to describe not just a psychological and affective phenomenon, but also a social structure or mating system (either social monogamy or just pair living). In this review, we ask the questions: What has been the historical definition of a pair bond? Has this definition differed across taxonomic groups? What behavioral evidence do we see of pair bonding in these groups? Does this observed evidence alter the definition of pair bonding? Does the observed neurobiology underlying these behaviors affect this definition as well? And finally, what are the upcoming directions in which the study of pair bonding needs to head?
Chapter
Liebe und Anerkennung sind elementare Strukturmerkmale von Paar- und Familienbeziehungen. In diesem Beitrag werden im Anschluss an einen historischen Abriss drei theoretische Ansätze unterschieden, mit denen sich ihre soziale Bedeutung genauer bestimmen lässt: Als normative Orientierungen, als gesellschaftliche Deutungsmuster und als interaktive Praxis in Paar- und Familienbeziehungen. Als Variante der letztgenannten Strategie wird die Anerkennungstheorie von Axel Honneth vorgestellt. Weiterhin werden Erklärungsansätze erörtert, die Liebe und Anerkennung in der alltäglichen Kooperation des Paares sowie in der außeralltäglichen Logik des Gabentauschs identifizieren.
Article
Full-text available
Advert for Cogent Psychology Publish your Policy Brief rapidly today and inspire change for tomorrow. Banner advert for Australian Journal of Psychology, now open access Full Article Figures & data References Citations Metrics Reprints & Permissions Get access Accepted author version Abstract Most studies on mammalian caregiving and attachment have focused on the mother-child relationship, particularly in humans. Yet, changing societal roles of male caregivers have highlighted the necessity for research with fathers. In this study, we examined the volume of the hypothalamus, an important subcortical brain area for caregiving and attachment, in a sample of N=50 fathering (child age 5-6 years) and N=45 non-fathering men using a novel technique to identify the human hypothalamus in 3T MRI. Furthermore, we employed three self-report measures to assess interindividual differences in adult attachment style across all men and caregiving beliefs in fathers. While we did not observe any significant difference in hypothalamus volume between fathers and non-fathers or associations between hypothalamus volume and self-reported adult attachment style across all men, self-reported caregiving beliefs were positively related to total hypothalamus volume in fathers. A follow-up analysis showed that fathers’ self-reported belief that a father’s role is important to child development was specifically related to tuberal hypothalamus volume, while self-reported enjoyment of spending time with the child was not associated with volume in hypothalamus sub-regions. Together, these findings suggest that interindividual variability in self-reported caregiving beliefs in fathers is related to brain structure, warranting further research.
Article
Full-text available
This article provides a narrative review of what is known about romantic love and sleep variations and provides possible explanations for the association. Romantic love and sleep are described using a comprehensive, unifying framework advocated by Tinbergen. We summarise the findings of studies investigating the relationship between romantic love and sleep. Sleep variations are associated with romantic love in adolescents and young adults. We then detail some proximate mechanisms that may contribute to sleep variations in people experiencing romantic love before considering potential evolutionary functions of sleep variations in people experiencing romantic love. The relationship between symptoms of psychopathology and sleep variations in people experiencing romantic love is described. With the current state of knowledge, it is not possible to determine whether sleep variations associated with romantic love are adaptations or by-products of romantic love. We conclude by proposing areas for future research.
Article
Questo lavoro si propone di presentare l'attuale stato dell'arte sul tema della dipendenza affettiva, una forma di amore ossessivo ed esasperato nei confronti del proprio partner, che nuoce al benessere della persona. Nella prima parte ven-gono trattate la definizione, la fenomenologia e la prevalenza di questa condizio-ne. Vengono inoltre esposte le principali teorie riguardanti l'inquadramento noso-grafico del problema e le considerazioni diagnostiche per differenziarlo da patolo-gie simili. La seconda parte dell'articolo riporta invece le varie ipotesi sull'eziologia della dipendenza affettiva, le principali misure per il suo assessment e i trattamenti che ad oggi sono stati proposti. Nel complesso si evidenzia che, sebbene si discuta da tempo di dipendenza affettiva, tuttora la letteratura a riguardo risulta fram-mentaria e poco chiara, il che è da considerarsi, a detta degli autori, come il princi-pale limite da superare per poter aiutare efficacemente chi soffre di tale condizio-ne.
Chapter
This chapter discusses wellbeing research on other life domains besides those covered in the previous chapters. Specifically, the chapter describes research in spiritual wellbeing, political and national wellbeing, environmental wellbeing, educational wellbeing, and sexual wellbeing.