Content uploaded by Heitor B. F. Fernandes
Author content
All content in this area was uploaded by Heitor B. F. Fernandes on Aug 02, 2015
Content may be subject to copyright.
Evolutionary Behavioral Sciences, May 4, 2015 (In press).
Authors version
Are negative postcoital emotions a product of evolutionary
adaptation? Multinational relationships with sexual strategies,
reputation, and mate quality
Heitor B. F. Fernandes*
Federal University of Rio Grande do Sul
Leif Edward Ottesen Kennair
Norwegian University of Science and Technology
Claudio S. Hutz and Jean C. Natividade
Federal University of Rio Grande do Sul
Daniel J. Kruger
University of Michigan
* Correspondence concerning this article should be addressed to Heitor B. F. Fernandes,
Universidade Federal do Rio Grande do Sul, Instituto de Psicologia, Ramiro Barcelos
2600/101, Porto Alegre – RS, Brazil. E-mail: heitor.barcellos@ufrgs.br
Abstract: Negative postcoital emotions (NPEs) are understood as a disorder by some authors, but little
is known about their evolutionary significance, etiology, and prevalence. We surveyed samples
from the United States, Canada, Brazil, and Norway to test predictions regarding the following
evolutionary hypotheses: Three groups of NPEs exist, related to (a) having a lesser or (b) a greater
perceived desire for bonding and commitment than one’s partner, or to (c) the maintenance of sexual
reputation. Additionally, (d) we hypothesized a Sex by NPE dimension interaction, whereby men have
higher levels of NPEs related to a lesser perceived desire for bonding relative to women, and women
have higher levels of NPEs related to greater perceived desire for bonding relative to men. Results
corroborated the existence of the three dimensions of NPEs, and the associations found between
them and indicators of mating effort, attachment anxiety, relationship satisfaction, and mate quality
supported most predicted design features across samples. The hypothesized sex differences were
supported in all samples. We argue that NPE factors have an important functional basis in sexual
strategies, and the factor comprising guilt, shame, and related emotions facilitates the maintenance of
sexual reputation. The capacity to experience NPEs appears to have evolutionary functions, and we
question its classification as pathological, considering the harmful dysfunction theory of pathology.
Finally, we report prevalence data indicating that NPEs are much more common than previously
speculated, with frequencies that were highly comparable across samples.
Keywords: cross-national, harmful dysfunction, negative postcoital emotions, sex differences, sexual strategies
Positive and negative valences are a fundamental feature of most theories of emotions (Barrett,
2006; Nesse & Ellsworth, 2009): emotions are understood as either pleasurable or aversive,
because they are products of adaptive mechanisms selected to respond to situations containing
either threat or opportunity (Nesse, 1990). The transition from sexual intercourse to the postcoital
time interval (Kruger & Hughes, 2010), which is the time after sexual intercourse that individuals
in a couple may spend together and interact, has been shown to sometimes elicit several negative
emotions in some individuals (Bird, Schweitzer, & Strassberg, 2011; Burri & Spector, 2011;
Campbell, 2008) both with and without orgasm having been reached (Burri & Spector, 2011).
Awareness about negative postcoital emotions (NPEs) is neither recent nor rare (see Kinsey,
1953; Bird et al., 2011), however current data about NPEs are limited and disparate for each
sex. Two recent studies investigated the prevalence and several possible predictors of female
postcoital sadness and tearfulness (Bird et al., 2011; Burri & Spector, 2011) and mood swings
(Burri & Spector, 2011); lifetime prevalence was 32.9% (Bird et al., 2011), and 7.7%
experienced such emotions in a persistent way (Burri & Spector, 2011). NPEs are speculated to
be even more common in men, based largely on clinical data (Sadock & Sadock, 2008).
Moreover, reasons for regret, disappointment (Campbell, 2008; Paul & Hayes, 2002), shame,
and guilt (Campbell, 2008) have been studied in both sexes after short-term sexual encounters.
Nevertheless, the prevalence of such emotional experiences is still unknown, and those studies
did not focus in the postcoital time interval only.
A comprehensive characterization of this phenomenon is still much in need, to investigate
the prevalence of emotions other than sadness, tearfulness and mood swings, and whether
NPEs are (a) one set of emotions, (b) different groups of emotions, or (c) emotions that are
independently triggered. Also lacking is evidence of whether or not NPEs are evolutionary
predictable, adaptive responses to specific
mating contexts and sex-specific stable adaptive
problems, as can be studied from an evolutionary psychological perspective (Buss,
1995; Buss & Schmitt, 1993).
Association of sexual difficulties with postcoital sadness and tearfulness seems to be small in
size (Bird et al., 2011). Classification of NPEs, therefore, appears not likely to be subsumed to
already-existing postcoital conditions. Thus another challenge is to explore the etiology of NPEs,
especially considering that overall psychological distress and reports of past sexual abuse seem to
explain only a small portion of variance of postcoital sadness and tearfulness in women (4.1%
and 2.5% respectively; Bird et al., 2011).
Some authors suggest the classification of NPEs as a sexual disorder (Prabhakar & Balon, 2010;
Sadock & Sadock, 2008), and there are reports of clinical treatment of NPEs (Friedman, 2009).
Nevertheless, in accordance with the harmful dysfunction definition of disorder (Kennair, 2003,
2011; Wakefield, 1999, 2007), we propose that a full understanding of NPEs and whether they
ought to be classified as disorder should take into account evidence of evolutionary function or
dysfunction, in addition to any evidence of personal or interpersonal nuisance. Suffering or
negative affect, by itself, is not enough to classify NPEs as a disorder, and emotions perceived
as negative or distressing may occur to help solve adaptive problems (see Kennair, 2011).
Relations between NPEs and attachment styles have been previously explored (e.g.,
Brennan, Clark, & Shaver, 1998; Gentzler & Kerns, 2004); however, NPEs were assumed to
be a one-factor variable. To our knowledge, no other studies have been conducted on the possible
associations between NPEs and human sexual strategies, rendering an analysis of functionality
with previous data impossible. We hypothesize that NPEs have a functional basis, and will,
therefore, attempt this analysis in the current paper.
Evolutionary Significance of Negative Postcoital Emotions
Animals often undergo profound behavioral changes following mating activity in ways that
are adaptive (Clyne & Miesenböck, 2009), and for humans that may be a prime time for bonding
and for the establishment or reinforcement of commitment (Kruger & Hughes, 2010).
It has been shown that postcoital emotional changes occur both in men and in women. After
first-time sexual intercourse, a negative change in perceptions of the partner’s sexual
attractiveness has been shown to occur mostly in men, especially in those who have had the
greatest number of sex partners (Haselton & Buss, 2001). This affective shift probably had
adaptive functions in facilitating the reduction of the risks to men of making maladaptive
ommitments, and it is an integral part of male short-term mating psychology (more about sexual
strategies in Buss & Schmitt, 1993).
In contrast, after short-term sexual encounters, women, compared to men, have reported
greater levels of vulnerability, dependency (e.g., Townsend, 1995; Townsend, Kline, &
Wasserman, 1995), love, emotional involvement, and commitment (Haselton & Buss, 2001),
and females are more likely to engage more in postcoital behaviors related to bonding than men
(Hughes & Kruger, 2011). Overall, females also report a more negative affective response
than men when anticipating sexual rejection after a one-night stand (de Graaf & Sandfort,
2004). These postcoital emotional shifts may provide women with the motivation needed to
pursue long-term commitment, as a way of gaining access to resources and paternal care for her
offspring. In fact, women report experiencing a greater willingness to get involved in short-term
sexual encounters when there is a chance of forming a long-term relationship (Shackelford,
Goetz, LaMunyon, Quintus, & Weekes-Shackelford, 2004), and when the potential partner is
described as having good parental skills (Surbey & Conohan, 2000). Sex differences also seem to
exist in the satisfaction with postcoital interactions, supporting hypotheses derived from evolutionary
theory on reproductive strategies (Kruger & Hughes, 2010).
Sexual interactions can also lead to regret, shame, self-blame, and guilt in men and women
at least partially for different reasons (Campbell, 2008; Galperin et al., 2013; Kennair, Bendixen,
& Buss, 2015; Paul & Hayes, 2002; Townsend, 1995; Townsend & Wasserman, 2011), and
they appear to sometimes be activated during the postcoital time interval (Paul & Hayes, 2002).
Recent studies have indicated that, whereas men more than women regret poorly chosen sexual
inactions (i.e., not having done something that they wish they had), women more than men
regret poorly chosen sexual actions (i.e., having done something that they wish they had not;
Galperin et al., 2013; Kennair et al., 2015). Regret, along with shame, guilt, and remorse (emotions
which have received less attention in studies on postcoital contexts), are hypothesized to regulate
social reputation, facilitating social reincorporation, and to appease others after transgressions
of social standards (for a review, see Fessler, 2004). It is important to examine the postcoital
activation pattern of such emotions, as sexual reputation is an essential component of social
reputation for both sexes (Buss & Schmitt, 1993; Campbell, 2008; Srivastava & Beer, 2005).
Aims and Hypotheses
Groups of Negative Postcoital Emotions
Different adaptive problems encountered recurrently in different situations throughout
evolutionary history are likely to have led selection to favor the activation of different sets of
emotions that facilitate advantageous solutions to each problem (Barrett, 2006; Nesse, 1990;
Nesse & Ellsworth, 2009). Based on this premise, we expect different groups of NPEs to exist,
which should correspond to different evolutionarily-recurrent postcoital contexts. Assuming that
throughout human evolutionary history, in the postcoital time interval the optimal amounts of
bonding and commitment were different for each sex and for individuals with different sexual
strategies, we propose that groups of NPEs may be adaptive responses elicited by a perceived
mismatch with sexual partners in desire for bonding and commitment in the following ways:
Hypothesis I: One group of NPEs should be related to having a lesser desire for bonding and
commitment than one’s partner, facilitating detachment from unwanted relationships. Emotions
such as disgust for one’s partner, irritability, a need to be alone, and apathy are predicted to be
in this group.
Hypothesis II: A second group of NPEs should be related to a greater desire for bonding
and commitment than perceived in one’s partner, helping to secure investment and
commitment from the partner. Emotional states such as feeling rejected, a need to be
comforted or for reassurance, insecurity, and feeling like crying (considering that, although
crying is not an emotion, it has been argued to signal need, attachment, and helplessness;
Hasson, 2009; Miceli & Castelfranchi, 2003) are predicted to be in this group.
Additionally, sexual interactions sometimes involve factors that can jeopardize one’s social
reputation, such as the impression that one has been too promiscuous and easy, involvements
with partners of much lower mate value, infidelity and a fear of being detected, rejection,
and so forth. Considering that, we propose that another group of emotions has been selected:
Hypothesis III: A third group of NPEs should be related to the maintenance or the
recuperation of social reputation after sexual intercourse, including emotions such as remorse,
shame, and guilt.
Sex Differences in NPEs
Although all groups of NPEs should be an integral part of both sexes’ behavioral repertoire,
considering the sex differences reviewed above we propose the following:
Hypothesis IV: Sex differences congruent with the Sexual Strategies Theory (Buss &
Schmitt, 1993; Buss, 2003) will be found for NPEs. We predict that the first and second
groups of NPEs will be differentially activated in the sexes. Specifically,
we predict that
men will report a more positive difference than women in their experiences of the groups of
NPEs related to a lesser and a greater desire for bonding than one’s partner; that is, men’s
levels of the first hypothesized factor of NPEs minus their levels of the second hypothesized
factor of NPEs are predicted to be greater than women’s levels of the first factor of NPEs
minus their levels of the second factor of NPEs (and by necessity the reverse would be
expected for women).
Here we follow the logic forwarded by Sagarin and colleagues (Sagarin, 2005; Edlund & Sagarin,
2009; Sagarin et al., 2012) developed for studies of sex differences in jealousy, whereby interactions
of Participant Sex by Jealousy type (sexual vs. emotional) are considered the most relevant test of
the evolutionary hypothesis of sex differences, and we argue that analyses of sex differences on
NPE factors ought to consider the Participant Sex by NPE factor interaction as the main test as well.
This logic is based on the fact that reproductive competition is mainly intrasexual, and thus
evolutionary theory does not imply that selection pressures boosted men’s levels of NPEs related to
a lesser desire for bonding above women’s, or that selection pressures boosted women’s levels of
NPEs related to greater desire for bonding above men’s (Sagarin et al., 2012). Finally:
Hypothesis V: The overall frequency and intensity of the third group of NPEs, potentially
related to the maintenance or recuperation of social reputation after sexual intercourse, should
not present sex differences, as recent studies indicate that the relevant locus of sex differences
in this domain is in the reasons for presenting regret and related emotions. In other words,
sexual reputation should be a concern for both sexes and as such elicit guilt, shame, remorse,
and related emotions similarly.
Evolutionary and Social Predictors of the Factors of NPEs
Our third aim is to examine the differential relationships of the groups of NPEs with mating
effort, relationship satisfaction, and differences in mate value beyond the effects of sex (i.e., not
explained by sex differences, but rather by potentially adaptive individual differences and by life
contexts). This aim follows from the proposition that potentially adaptive variation in sexual
strategies exists also within each sex (e.g., Bailey, Kirk, Zhu, Dunne, & Martin, 2000; Buss &
Hawley, 2010; Figueredo et al., 2004; Gangestad & Simpson, 2000), and from the basic premise
that within-individual variation in the experience of emotions can occur depending on the life
context of the individual, which includes one’s relationship status and satisfaction with one’s
romantic relationship.
Mating effort refers to the amount of energy, time, or other key resources invested in
competing for and retaining short-term mates.
1
One of the most common trade-offs in animals is
that between mating effort and parental effort, which refers to the amount of resources invested
in rearing and defending the offspring (Magrath & Komdeur, 2003; McGlothlin, Jawor, &
Ketterson, 2007), and usually also refers to retaining a long-term mate, which facilitates the
survival of the offspring (Gwynne, 1984; Rowe, Vazsonyi, & Figueredo, 1997). Another
important trade-off is that between reproductive effort and somatic effort (Magrath & Komdeur,
2003), which refers to resources devoted to the continued survival of the individual organism.
Trade-offs such as these two are central to human individual differences in what is known as
life history speed: a continuum that varies from fast to slow (Ellis, Figueredo, Brumbach, &
Schlomer, 2009; Pianka, 1970; van Schaik & Isler, 2012), where fast life history is characterized
by traits such as high mating effort, early onset of reproduction, and impulsivity, and slow life
history by traits such as high parental effort, community building, and somatic maintenance.
Several constructs commonly assessed in evolutionary and social psychology are indicators
of mating effort. Sociosexual orientation, which refers to the degree of promiscuity in one’s
desire, attitudes, and behavior (Penke & Asendorpf, 2008; Simpson & Gangestad, 1991), has
1
As Rowe et al. (1997) stress, the word mating is used somewhat euphemistically in this context, as the term mating
effort refers to investments in obtaining and retaining short-term sexual partners. To make this explicit, some authors
call this promiscuous mating effort instead (Gwynne, 1984), and specify that non-promiscuous mating effort is
positively associated with, or a component of, parental effort, and decreases the probability of the individual seeking
and reproducing with other partners. In line with most of previous literatures, we will refer to promiscuous mating
effort simply by the term mating effort.
been understood as an indicator of the mating effort versus parental effort trade-off (Penke &
Asendorpf, 2008; Simpson, Wilson, & Winterheld, 2004). Adult romantic attachment styles
have also been argued to reflect that trade-off, rather than reflecting only attachment processes
per se (Kirkpatrick, 1998; Kruger & Fisher, 2008), especially the avoidant-versus-secure
attachment continuum (Jackson & Kirkpatrick, 2007). Overall mate value influences
and is
also associated with reproductive strategies (Penke & Asendorpf, 2008; Schmitt, 2005), with
higher levels leading to higher discriminating behavior toward prospective romantic partners
(Buss & Schmitt, 1993; Edlund & Sagarin, 2010), and thus mate value is a positive component
of slow life history and is inversely related to mating effort (Olderbak, Gladden, Wolf, &
Figueredo, 2014).
Individuals with higher mating effort are more likely to get involved in sexual activities with
partners with whom there are mismatches in desire for commitment and in general mate value
(Figueredo & Wolf, 2009 demonstrated that faster life history individuals disassortatively mate
more strongly), to get involved in sexual infidelity (Mattingly et al., 2011), to perpetrate and to
be a victim of sexual harassment (Kennair & Bendixen, 2012; Mouilso & Calhoun, 2012;
Perilloux, Duntley, & Buss, 2011), to experience postcoital dissatisfaction, low levels of
postcoital bonding (Kruger & Hughes, 2010), and higher levels of negative emotions in romantic
relationships (Simpson, 1990), and to be seen as too easy and promiscuous (Buss & Schmitt,
1993; Campbell, 2008). These correlates of mating effort negatively impact one’s social
reputation. Moreover, faster life history individuals report not only lower levels of relationship
satisfaction (Olderbak & Figueredo, 2009; Olderbak & Figueredo, 2010), but also lower
postcoital satisfaction and less postcoital bonding with their partner (Kruger & Hughes, 2010),
as a result of a mismatch with their partner in desire for bonding. Additionally, negative affect in
general is positively associated with mating effort (Kirsner, Figueredo, & Jacobs, 2009),
negatively associated with mate value (Kirsner et al., 2009), and is considered a component of
fast life histories (Figueredo et al., 2004). Considering all these known associations, we propose
the following:
Hypothesis VI: NPEs should be more frequent and more intense in individuals with higher
mating effort. This should apply to all three NPE factors, for the reasons outlined above.
Beyond the effects of mating effort, the residuals of the indicators that compose the mating
effort factor should predict NPE factors only weakly, as is expected when the direct effects
of a general factor are substantial.
High levels of investment in long-term relationships do not require the expression of neediness
or insecurity with one’s relationship, as demonstrated by the observation that attachment
avoidance is more strongly associated with mating effort than attachment anxiety (Fernandes,
Woodley, Hutz, & Kruger, 2015; Hazan & Shaver, 1987; Jackson & Kirkpatrick, 2007).
Considering that in the postcoital time interval attachment avoidance predicts lower proclivity
to establish relationship commitment and attachment anxiety predicts postcoital neediness (see
Kruger & Hughes, 2010 for an empirical test), we propose the following:
Hypothesis VII: The group of NPEs of avoidance of bonding should be more strongly
associated with mating effort than the group of NPEs of neediness and clinging. Still, we
expect NPEs of this latter type to present at least a weak positive relationship with
mating effort because individuals with high attachment anxiety appear to engage in
impulsive short-term mating while showing a heightened desire for long-term
relationships and romance (see Del Giudice, 2009), and also because individuals with low
mating effort are likely to be already successfully bonded and to have higher relationship
satisfaction, thus it is unlikely that they would benefit from romantic neediness. This
hypothesis, by necessity, also derives the testable prediction that NPEs of neediness and
clinging are especially related to attachment anxiety, which is to be expected based on the
fi that those with higher attachment anxiety tend to experience lower postcoital satisfaction
and long more for connection after sex (Kruger & Hughes, 2010).
Another important putative predictor of NPEs is relationship satisfaction. Dissatisfaction with
one’s relationship can be experienced for different reasons, such as perceiving an imbalance in
commitment and in investments desired by each partner, having an unfaithful partner, or one who
uses intense mate-retention tactics; as such, relationship satisfaction has been proposed to signal
that the one is incurring costs that outweigh the benefits propitiated by the relationship (Shackelford
& Buss, 2000). Considering that the many negative emotions are argued to have evolved to signal
threats to one’s fitness, we propose the following:
Hypothesis VIII: All groups of NPEs should be negatively related to relationship satisfaction,
as dissatisfaction can be triggered by many different causes of fitness
threats, and we aim to
examine this prediction with individuals who are currently in a relationship.
Finally, we aim to test whether disparities in mate value between the partners predict the
frequency and the intensity of NPEs. Mate value includes many qualities that tend to covary
(Kirsner et al., 2003). Romantic involvement with individuals of low mate value can lead to
fitness costs, therefore we propose the following:
Hypothesis IX: NPEs related to avoidance of bonding should be experienced by individuals of
higher perceived mate value than their partner after sexual involvement. Moreover, getting
involved with and committing to partners of lower perceived mate value may strongly
jeopardize one’s reputation, consistent with previous findings
(Paul & Hayes, 2002); we thus
expect higher levels of the group of NPEs related to the maintenance of reputation to be
exhibited by individuals of higher perceived mate value than their partner. The specific
variance of self-rated mate value and of the perceived mate value of one’s partner should
present weak residual effects.
Method
Participants
Four samples from different countries were used for the present study. We recruited participants
from Brazil, the United States, Canada, and Norway. Individuals who were not fluent in the
respective language used in the questionnaire in each of these countries or who were younger
than 18 years of age were excluded from participation in the study. Among those who took
part in the data collection, criteria for inclusion in the analyses were as follows: being exclusively
or mostly attracted to individuals of the opposite sex, having had sexual intercourse, and being up
to 30 years of age, because of the well-known reproductive changes that occur in the 30s (e.g.,
Dabbs, 1990; Dunson, Baird, & Colombo, 2004), and as changes at this age in the refractory
period after sexual intercourse in males have also been identified (Dunn & Trost, 1989). This study
was approved by appropriate institutional ethics boards in all countries included.
Comparisons between Brazilian, Norwegian, American, and Canadian populations may be of
interest when testing potential human universals related to sexual strategies and sex differences.
This is especially because of differences found between these countries regarding
conceptualizations of the development of heterosexual encounters (DeSouza & Hutz, 1996), female
acceptance of male sexual advances, openness to displays of nudity and sexuality, female
subordination to men (DeSouza, Pryor & Hutz, 1998), acceptance of female sexuality (Træen,
1994), and overall liberal attitudes toward sexuality (Bjerke, Williams, & Wathne, 1989; Widmer,
Treas, & Newcomb, 1998). Moreover, according to the Global Gender Gap Report (Bekhouch,
Hausmann, Tyson, & Zahidi, 2013), in 2011 and 2012, when most of the data collection for the
current paper were conducted, Norway was considered the second and then the third most
gender-equal country of 135, the United States the 17th then the 22rd, Canada the 18th then
the 21st, and Brazil the 82nd then the 62nd.
Brazilian sample. Participants were 517 individuals (70.2% females), students and otherwise,
from all five regions of Brazil (34.8% from the Southeast, 33.6% from the South, 29.1% from the
Northeast, and 2.5% from other regions). Male participants’ mean age was 23.6 (SD
=
3.0), and
female participants’ was 23.3 (SD
=
2.9); 55.2% of males and 62.6% of the females reported
being currently involved in a committed relationship.
Midwestern-American sample. Participants were 349 students from two public Midwestern
universities in the United States (65.6% females). Male participants’ mean age was 19.4 years (SD
=
1.5), and female participants’ was
19.6 (SD
=
2.0); 40.9% of males and 57% of females reported being currently involved in a
committed relationship.
Anglo-American sample. Participants were 374 individuals (76% females), students and
otherwise, drawn from all regions and divisions of the United States specified by the United
States Census Bureau, and from seven of the 13 Canadian provinces and territories. Male
respondents’ mean age was 22.1 (SD
=
3.8), and female respondents’ was 21.5 (SD
=
3.5);
55% of males and 59% of females reported being currently involved in a committed relationship,
and 11.6% of the males reported having at least one child, whereas 18.7% of the females
reported having one or more children. 34% of participants were from the South of the U.S., 23%
from the West, 26% from the Midwest, 12% from the Northeast, and the remaining 5% from the
Southern provinces of Canada. The most represented Census Bureau divisions of the United States
were division 5 (South Atlantic) with 24%, division 9 (Pacific) with 19%, and division 3 (East
North Central) with 18%.
Norwegian sample. Participants were 533 students (73% females) from a Norwegian university.
Students from different subjects and campuses were recruited. Male respondents’ mean age was
21.9 (SD
=
2.4), and female respondents’ was 21.3 (SD
=
1.8); 49% of males and 55.7% of
females reported being currently involved in a committed relationship. Students at this university
provide a strongly homogenous group (Grøntvedt & Kennair, 2013), almost all being ethnic
Norwegian, middle class, and secularized state church Protestants or nonbelievers.
Data for the 19 Canadian individuals who volunteered to participate in the Anglo-
American data-collection wave were included in the same sample instead of excluded because (a)
no significant (p
<
.05) differences were identified when comparing these participants to the
American participants in any trait assessed in this study; (b) as extensively reviewed in the literature
(see Grabb & Curtis, 2005), there are only very weak differences between American and Canadian
cultures in general and in psychosocial dimensions; (c) Gender Gap Reports (see above) indicate
that the U.S. and Canada have strikingly similar gender inequality patterns; and (d) all Canadian
participants included in Sample 3 were from provinces that border the United States. Participants
from the exclusively Midwestern-American sample were not combined with those from this broader
Anglo-American wave of data collection even though the latter included other Midwestern-
American participants, as sampling procedures were considerably different in these two waves: All
participants from the exclusively Midwestern-American sample, but not from the Anglo-American
sample, were university students, course credits were awarded for participants of the Midwestern-
American sample whereas no incentive or compensation was offered for those in the Anglo-
American sample (see Procedures), and the questionnaire fi out in the Midwestern-American
sample included additional scales intended for parallel studies (not included in this manuscript).
Perhaps partly as a consequence, significant (p
<
.05) differences of moderate effect size were
identified for several traits (see Measures and Results for a description of these traits) between the
Midwestern-American and the Anglo-American samples: sociosexual orientation, t(639.52)
=
2.39,
attachment anxiety, t(578. 29)
=
2.57, life history speed, t(597.17)
=
4.16, self-rated mate value,
t(659)
=
6.41, perceived partner mate value, t(662.04)
=
4.18, and the intensity of experiences of the
NPE factor related to greater perceived desire for bonding and commitment than one’s partner, t(566.53)
=
2.43.
Measures
Initial questions sought background information regarding sex, age, sexual orientation,
relationship status, and previous sexual experiences. To measure the frequency and the intensity
of NPEs, we created an inventory containing 23 negative emotions (see Table 1, and the Results
section for an analytical description of their factorial pattern), based on well-known taxonomic
categorizations of emotions (Ortony & Turner, 1990; Shaver, Schwartz, Kirson, & O’Connor,
1987). Three of the 23 emotional states included were not present in these categorizations, and
we incorporated them in the inventory as we considered them to be relevant to the study of
interpersonal relationships: need to be alone, need to be comforted (which are relatively common in
social relationships and may reflect the quality of bonds and one’s disposition toward them), and
mental confusion (a mental state that is relatively common after intense or potentially traumatic
situations, such as sexual assault; Dunmore, Clark, & Ehlers, 1999). Synonyms or near-synonyms
of any NPEs already present in the inventory were not added, to avoid inflating their factorial
associations. Moreover, some near-synonyms (such as fear and dread) differ from each other
in meaning because of intensity (e.g., Flexner, 2003; Merriam Webster, 2010), a dimension that
we explicitly assessed (see below). We included two versions of the Negative Postcoital Emotions
inventory in measurements in all samples, with 5-point Likert-type scales. The first version assessed
the overall frequency (based on all current and past relationships) of NPEs experiences (where 1
represented never; and 5, all the time), whereas the second assessed the intensity of the emotions
experienced (where 1 represented no intensity; and 5, extremely intense). Intensity was reported
based only on the last occasion the participant experienced NPEs.
Table 1. Principal Axis Factor analysis of the NPEs intensity scale (Oblimin rotation)
Factor loading
Negative post-coital emotions
Need for bonding
Maintenance of
reputation
Avoidance of
bonding
Need to be comforted
.72
-.06
-.01
Feeling of worthlessness
.70
.21
-.03
Tearfulness or feeling like crying
.67
-.11
.01
Feeling of helplessness
.64
.01
.14
Sadness
.60
-.03
.19
Feeling rejected
.59
.12
.04
Loneliness
.56
.09
.17
Insecurity
.52
.23
-.02
Fear
.39
.24
.03
Mental confusion
.36
.19
.22
Uneasiness
.27
.21
.27
Shame
.15
.76
.00
Guilt
.07
.69
.06
Self-disgust
.17
.56
.12
Remorse
-.03
.50
.29
Irritability
.04
-.12
.69
Need to be alone
-.05
.04
.63
Disgust for partner
-.11
.20
.63
Anger
.19
-.03
.59
Apathy or emotional blunting
.05
.04
.51
Pity
.02
.14
.44
Frustration
.21
.06
.40
Agony
.27
-.04
.37
Note. Items with preferential loadings on a particular factor and which were thus included in the
estimation of that factor are highlighted in bold. Items that presented factor loadings <.30 or between
.20 and .40 in more than one factor were not included in the estimation of any factor.
The Sociosexual Orientation Inventory— Revised (SOI-R; Penke & Asendorpf, 2008) was
employed as a measure of sociosexuality, which is an indicator of mating effort, in all samples.
This corresponds to the level of sociosexual unrestriction, or willingness to engage in uncommitted
sexual relationships, in three domains: past behavioral experiences, sexual desire, and attitudes
toward uncommitted sexual interactions, and scores on the three subscales can be summed to
create a global measure of sociosexual orientation (Penke & Asendorpf, 2008). The 5-point version
developed by Penke and Asendorpf (2008) was used, which might be more appropriate for samples
with less test-experienced participants (although a 9-point version was also made available and has
similar internal consistency). Cronbach’s alpha was .89 in the Brazilian sample, .86 in the
Midwestern-American sample, .68 in the Anglo-American sample, and .85 in the Norwegian
sample.
The Experiences in Close Relationships Scale-Short Form (ECR-S; Wei, Russell,
Mallinckrodt, & Vogel, 2007) was employed as a measure of attachment styles. This taps two
factors: avoidant and anxious attachment. Attachment avoidance is defined as involving fear of
interpersonal intimacy and dependence, and reluctance to self-disclose to romantic partners, and is
an indicator of mating effort (Fernandes et al., 2015; Jackson & Kirkpatrick, 2007). Attachment
anxiety is understood as including excessive need for approval from the romantic partner, fear of
abandonment or rejection, and distress when one’s partner is unavailable (Wei et al., 2007).
Participants were instructed to think of their past and current partners altogether. Cronbach’s alpha
was .67 for Attachment avoidance, and .75 for Attachment anxiety in the Brazilian sample; .66 and
.83 in the Midwestern-American sample; and .73. and .78 in the Anglo-American sample. This scale
could not be used in data collections in the Norwegian sample due to time constraints imposed by
the in-class data-collection design, and thus other more specific measures of mating effort (such as
sociosexual orientation and relationship commitment) were prioritized for the data collection in
this sample. Considering that attachment anxiety is only weakly associated with sociosexual
preferences (Hazan & Shaver, 1987; Jackson & Kirkpatrick, 2007), and that in all samples it
presented consistently very low and nonsignificant correlations with the Mini-K (r
<
.10, p
>
.05),
we did not consider it as an indicator of mating effort, and as such only attachment avoidance
was included in the estimation of the mating effort factor.
The Mate Value Inventory (MVI-7, Kirsner et al., 2003) was used in two forms to measure
both the perceived personal mate value and the perceived mate value of a real sexual partner in all
samples. This scale corresponds to a one-factor proxy for genetic quality and estimates one’s
bargaining power in the mating marketplace, assessing many components of mate quality
(Kirsner et al., 2003) without unduly focusing on just one component (Edlund & Sagarin, 2010).
Overall mate value is associated with various sexual-strategy traits (e.g., Penke & Asendorpf,
2008), with higher levels leading to higher discriminating behavior toward prospective romantic
partners (Buss & Schmitt, 1993; Edlund & Sagarin, 2010). Self-rated mate value is strongly
associated with indicators of sexual strategies and mating effort, being sometimes included as a
life history indicator (Olderbak et al., 2014). Respondents who reported having already
experienced one or more NPEs were instructed to think of the last partner with whom they
experienced NPEs. The other participants were instructed to think of their current partner or last
partner. Cronbach’s alpha for the Personal mate value form was .77, and .89 for the Partner mate
value form in the Brazilian sample; .87 and .92 in the Midwestern-American sample; .87 and
90 in the Anglo-American sample; and.78 and .91 in the Norwegian sample.
The Mini-K Life History Strategy Short Form (Figueredo et al., 2006), whose validity as a
psychometric measure of life history speed was recently demonstrated in a psychometric metaanalysis
(Figueredo et al., 2014; see also Figueredo et al., 2015), was used in the Brazilian, Midwestern-
American, and Anglo-American samples, but data collection with this scale was not possible in
the Norwegian sample due to time constraints imposed by the in-class datacollection design, and
thus other more specific
measures of mating effort (such as sociosexual orientation and relationship
commitment) were prioritized for the data collection in this sample. The Mini-K is a short form of
the Arizona Life History Battery (Figueredo, 2007), which also includes insight, planning and
control, mother/ father relationship quality, family social contact and support, friends social contact
and support, experiences in close relationships, general altruism, and religiosity as measures. Life
history speed has the mating effort-parental effort trade-off as a central component (Figueredo et al.,
2004; Stearns, 1992). Cronbach’s alpha was .78 in the Brazilian and Midwestern-American samples,
and .82 in the Anglo-American sample.
We adapted nine additional items from the Satisfaction and the Commitment factors of the
Relationship Questionnaires (Rusbult, 1983) and used them to assess satisfaction with an
ongoing relationship, and perceived personal commitment to it (an indicator of mating effort) in the
Brazilian, Anglo-American, and Norwegian samples. Inclusion of these scales for data collection
in the Midwestern-American sample was not possible due to time constraints imposed by student
participation, and thus other measures with more extensive demonstrations of validity in the
Anglophone literature were prioritized for the data collection in this sample. Only individuals
currently involved in a relationship, casual or otherwise, were instructed to answer these items.
Cronbach’s alpha for the Satisfaction factor were .84 and .80 in the Brazilian and Norwegian
samples respectively; and for the Commitment factor they were .83 and .80 in the Brazilian and
Norwegian samples respectively.
Procedures
Instruments used in the Brazilian sample were translated to Brazilian Portuguese by a bilingual
researcher, back-translated to English by a second bilingual researcher, and finally the necessary
adjustments were made by a native speaker of American English. Instruments used in the
Norwegian sample were translated to the Norwegian language by two bilingual researchers.
Participants responded to 205 questions and items in the Brazilian and Anglo-American samples,
200 in the Midwestern-American, and 125 in the Norwegian sample, taking around 40 minutes to
complete the questionnaire in the first three samples, and around 20 to 25 minutes in the Norwegian
sample. Most studies indicate that survey length and data quality are not associated (for a
comprehensive review see Rolstad, Adler, & Rydén, 2011), thus we have not taken into
consideration the different survey lengths across samples.
Of those who initiated the online questionnaires for the Brazilian, Anglo-American, and
Midwestern-American samples, 74%, 64%, and 100% completed the process respectively,
whereas 96% of those who initiated the penand-paper questionnaire for the Norwegian sample
completed it.
We forwarded a call for participants for the Brazilian sample to Brazilian universities, advertised
it on Laboratory of Measurement’s website (http://www.ufrgs.br/psico-laboratorio/), and forwarded it
to its followers on social networks. Participants in the Midwestern-American sample took part in the
study in exchange for course credits, and as data collection in the other samples was conducted by
Brazilian and Norwegian researchers no incentives or compensations were offered, in conformity
with the local laws of these countries. All participants were informed that participation in the survey was
completely voluntary and anonymous.
As discussed and demonstrated by many authors (e.g., Cole, Bedeian, & Feild, 2006; Davidov
& Depner, 2011; Fouladi, McCarthy, & Moller, 2002; Gwaltney, Shields, & Shiffman, 2008;
Meade, Michels, & Lautenschlager, 2007; Riva, Teruzzi, & Anolli, 2003), the comparability of
results found with online and paper-and-pencil modes of data collection is extremely high across
psychological phenomena measured, therefore this is extremely unlikely to affect the validity of the
data-collection in the Norwegian sample compared to others.
We aimed to collect data for at least 300 participants in each sample, considering that, although
many sex differences in emotional experiences present moderate to large effect sizes, some have
been identified to be small (e.g., Campbell, 2008; Haselton & Buss, 2001; Hughes & Kruger,
2011), and the relationships among some of the variables included in this study have been
identified to be small in magnitude by meta-analyses (see Figueredo et al., 2014); as such, smaller
samples sizes would make it difficult to differentiate between nonsignificant effects and small
but consistent effects, inducing Type II errors.
Results
The Factor Structure of NPEs
Principal Axis Factor analysis was conducted using direct oblimin rotation to examine the
factorization of NPEs on a general dataset that combined all samples. The frequency of NPEs was
reported based on all previous sexual experiences combined and this does not inform us about the
extent to which the emotions cooccurred (i.e., the extent to which they were activated in
conjunction as opposed to in different circumstances or with different partners), whereas the
intensity of NPEs experienced was reported based only on the last event in which at least one NPE
was experienced, and this is informative not only of co-occurrence but also of the similarity of
the magnitude with which the NPEs were simultaneously activated; we thus used the data on the
intensity of NPEs for the factor analysis. Three factors were extracted according to both Horn’s
(1965) parallel analysis and Kaiser’s (1960) eigenvalue higher than 1.0 criterion, with eigenvalues
7.74, 1.37, and
1.22 (a fourth factor had an eigenvalue of .86, and a minimum of 1.12 was necessary for it to be
extracted according to parallel analysis), accounting for 49.13% of the variance in the intensity of
NPEs (KMO
=
0.94; x
2
=
13,134.96, df
=
153, p
<
.001). We computed coefficients
of
comparability (Everett, 1983; Everett & Entrekin, 1980; Nunnally, 1978) among the three samples
for each factor, and also between men and women in the dataset containing all samples combined.
The coefficient of comparability is a measure of the equivalence between factors extracted from
different samples, being especially useful to compare the factor pattern of different populations
(Everett & Entrekin, 1980) and to determine the number of reliable factors to be extracted across
samples (Everett, 1983), and is calculated based on the weights of each item on factor scores rather
than based on the items’ factor loadings, thus providing a more direct measure of factor
comparability than the commonly-used coefficients of congruence (Everett, 1983; Everett &
Entrekin, 1980). There was a high level of comparability for each sample pairing and between
men and women for all three factors (coefficient of comparability > .90 for all factors), indicating
that factor structures are highly similar across samples and sexes.
The three factors appeared to be related to (a) need for bonding (the term neediness NPE factor
will be used to refer to this common factor), comprising eight emotions; (b) maintenance of
reputation (the term reputation-maintenance NPE factor will be used to refer to this common
factor), comprising four emotions; and (c) avoidance of bonding (the term avoidance NPE factor
will be used to refer to this common factor), comprising six emotions (see Table 1), supporting the
predictions made for Hypotheses I, II, and III regarding which emotions would be activated in
conjunction. Correlations were .52 between factors 1 and 2, .64 between factors 1 and 3, and .53
between factors 2 and 3. Cronbach’s alpha for the intensity of the neediness NPE factor was
.89, .89, .88, and .83 in the Brazilian, Midwestern-American, Anglo-American, and
Norwegian samples respectively; .79, .91, .86, and .84 for the intensity of the reputation-
maintenance NPE factor; and .78, .81, .85, and .68 for the intensity of the avoidance NPE
factor. Regarding the factors based on the frequency of NPEs experienced, Cronbach’s alpha was
.86, .92, .88, and .84 for the neediness NPE factor in the Brazilian, Midwestern-American, Anglo-
American, and Norwegian samples, respectively; .80, .92, .90, and .85 for the reputation-
maintenance NPE factor; and .74, .88, .84, and .69 for the avoidance NPE factor.
Sex Differences in the NPE Factors
The predicted Participant Sex by NPE factor interaction (considering the avoidance NPE and the
neediness NPE factors) was found in all samples (see Figure 1). This was the case both for
frequency and for intensity of NPEs, supporting predictions made for Hypothesis IV.
We also conducted within-sex analyses comparing the neediness and the avoidance NPE
factors to further test the sex differences predicted in Hypothesis IV:
Figure 1. Sex by NPE factor interactions by sample. Panel A displays interactions based
on frequency of NPE factors, and Panel B based on intensity of NPE factors. Bars represent
±
1.0 standard error of the mean. Entries marked with an asterisk indicate significant (p <
.05) interaction.
Regarding frequency, women scored sig
nificantly (p
<
.05) higher in the neediness
NPE factor than in the avoidance NPE factor
in the Brazilian sample, t(342)
=
9.25,
Cohen’s d
=
.46; in the Midwestern-American
sample, t(232)
=
5.81, d
=
.23; and in
the
Anglo-American sample, t(282)
=
7.98, d
=
.34; but not in the Norwegian sample,
where
women scored equally in both factors within a
margin rounding error (1.437 and
1.438, respectively), t(383)
=
.09, d
=
.00. Men
scored significantly (p
<
.05) higher
in the
avoidance NPE factor than in the neediness
NPE factor in the Brazilian sample,
t(150)
=
4.77, d
=
.40; in the Midwestern-American
sample, t(121)
=
2.01, d
=
.09; in
the Norwegian sample, t(142)
=
6.61, d
=
.51; and
this effect was borderline significant
(p
=
.05) in the Anglo-American sample, t(90)
=
1.98, d
=
.13.
Regarding intensity, women scored signific
antly (p
<
.05) higher in the neediness NPE
factor than in the avoidance NPE factor in the
Brazilian sample, t(333)
=
6.88, d
=
.34; in the
Midwestern-American sample, t(224)
=
5.08,
d
=
.25; in the Anglo-American sample,
t(215)
=
5.41, d
=
.29; and in the Norwegian
sample, t(340)
=
2.29, d
=
.11. Men scored
significantly (p
<
.05) higher in the avoidance
NPE factor than in the neediness NPE factor in
the Brazilian sample, t(149)
=
3.03, d
=
.25; in
the Midwestern-American sample, t(112)
=
2.74, d
=
.19; and in the Norwegian sample,
t(125)
=
5.23, d
=
.44; but not significantly in
the Anglo-American sample, t(65)
=
1.55, d
=
.10.
Evolutionary and Social Predictors of the Factors of NPEs
To be able to test the predictive power of mating effort and its indicators on NPE factors, we
first examined the factorial pattern of putative indicators of mating effort assessed: Sociosexual
orientation, attachment avoidance, relationship commitment, overall life history speed, and one’s
own mate value. These variables presented moderate to high loadings on a common factor examined
with Principal Axis Factoring (with oblimin rotation) in all four samples (see Table 2), and only
one factor was extracted in all samples according to Horn’s (1965) parallel analysis. As the
Midwestern-American and Norwegian samples had one and two mating effort indicators
missing, respectively, before proceeding we assessed whether there was a high comparability
between the factors computed with missing indicators and the factor built with all five mating effort
indicators. The three versions of the mating effort factor presented extremely high consistency
among themselves (Cronbach’s alpha
=
.97 in the Brazilian sample, .98 in the Anglo-American
sample, which are the samples in which all three versions could be computed), thus indicating
they measured the same latent construct. Moreover, the coefficient of comparability among the three
versions of the mating effort factor ranged from .89 to .98, corroborating their high equivalence. We
thus employed multivariate imputation (Figueredo, McKnight, McKnight, & Sidani, 2000) to
build the common factor in the Midwestern-American and Norwegian samples.
Table 2. Principal Axis Factor analysis of indicators of the mating effort factor (Oblimin rotation)
Indicator
Factor loading
Brazilian
Midwestern-
American
Anglo-
American
Norwegian
Sociosexual orientation
.47
.44
.54
.52
Attachment avoidance
.57
.66
.68
–
Relationship commitment
-.73
–
-.81
-.69
Mini-K
-.57
-.69
-.62
–
Mate value self-rated
-.51
-.44
-.51
-.28
We proceeded to test the predictive power of the mating effort factor, its components,
relationship satisfaction, the difference in mate value between the respondents and their partners,
one’s mate value, and one’s partner’s mate value upon the NPE factors. Hierarchical general linear
model (GLM) analyses were conducted in a combined dataset containing all samples, with each
of the three factors of NPEs as outcome variables, for frequency and intensity of NPEs separately.
To also examine similarities and differences among the samples and between the sexes, we
introduced discrete variables that categorized the four samples and categorized the sexes as the
first predictors in the GLM analyses. This approach is also frequently used in cross-population
level studies and in comparative studies that aim to assess the true evolutionary associations
between traits, eliminating the influence of similarity within categories that is attributable to shared
historical, geographic, or cultural features (Pagel & Harvey, 1988; Stearns, 1983, 1992; see Mace
& Pagel, 1994 for a detailed discussion of the applications of phylogenetic controls to studies
with human populations). Applying this to our GLM analyses thus permitted avoiding an inflation
of the predictive power of the independent variables that would follow from including samples
from partially-different cultural or historical origins in the same analytical models. We entered the
categorical variables in the GLM analyses nested within each other: The fi categorical variable
separated the samples from countries that are highly developed and where settlement
colonization by Germanic peoples was predominant from the only sample from a developing
country with history of exploitative colonization by Iberian peoples (Brazil). The second
categorical variable separated North-American samples from the sample from the only
European country included (Norway). Finally, the third categorical variable separated the
Midwestern-American sample from the Anglo-American sample. Sex was entered as the
last categorical variable. The mating effort factor was then entered in the hierarchical
GLMs as the first
continuous predictor.
Because the variables included in the mating effort factor have theoretically highly comparable
levels of data aggregation, are not parts of one another, and are likely to influence each other
mutually rather than in a clear sequence, we entered all of them directly after the mating effort factor,
each in a separate hierarchical GLM, rather than entering all of them in the same model but in an arbitrary
order. This is because the latter procedure would produce only the residual effects of the mating effort
indicators entered after the other ones, rather than producing the effects of all mating effort indicators
residualized only against the categorical variables and against the mating effort factor. When including
relationship commitment and satisfaction in the GLMs, only those participants who were currently in
a relationship (committed or otherwise) and who filled out the NPE scales thinking about their current
relationship were selected, as the commitment and satisfaction scales measure those constructs with
regard to an ongoing relationship. Interaction terms between the categorical and the continuous
independent variables were entered after all main effects to examine whether important differences
exist among samples and between the sexes in the magnitude with which the continuous variables predict
the frequency and the intensity of NPE factors. Considering that these interaction terms were
numerous ad hoc tests, as opposed to the hypothesis-driven tests of the main effects being examined
with each of the continuous constructs, we created sets of interactions, each set involving the interactions
between a continuous construct and each of the four categorical variables, and examined the
significance of the effects of each of these sets of interactions up on the NPE factors. Only significant
interaction terms within a set that presented a significant effect upon an NPE factor were considered
significant interaction effects. This functions as a correction for multiple comparisons and is intended
to reduce the likelihood of incurring Type I errors for ad hoc tests.
Table 3 displays the results of GLMs with the frequencies of the NPE factors as outcome variables.
In Hypothesis V we predicted that men and women would present similar patterns of activation
in the maintenance of reputation factor, however women reported higher frequency of the
reputation-maintenance NPE factor than men, even though this effect was considerably small in
magnitude. In line with Hypotheses V and VI, the mating effort factor positively predicted the
frequency of all NPE factors, and it predicted the avoidance of bonding factor more strongly than
the need for bonding factor (Fisher’s z
=
2.28, p
<
.05). Residual attachment avoidance positively
predicted the avoidance and the reputation-maintenance NPE factors beyond the mating effort
factor, and similarly to the effects of mating effort upon the NPE factors, residual sociosexual
unrestriction was less positively associated with the neediness NPE factor than with the avoidance
NPE factor (Fisher’s z
=
2.65, p
<
.05), and was even negatively and significantly associated
with the neediness NPE factor. Residual life history speed, however, had effects that were
contrary to the mating effort factor, as it positively predicted the reputation-maintenance and
the avoidance NPE factors. As can be observed, however, overall the predictive power of all
residual mating effort indicators, entered after the relatively moderate effects of the mating
effort factor, was small, in line with Hypothesis VI.
Table 3. Semipartial correlations from hierarchical general linear models predicting the frequency
of NPE factors
Predictors
Order
NDF,
DDF
Semipartial correlations
Need for
bonding
Maintenance
of reputation
Avoidance
of bonding
Major historical/economic group
1
1, 1650
-.087*
.005
-.032
Continent
2
1, 1650
-.188*
-.101*
-.075*
Region
3
1, 1650
-.008
.033
.050*
Sex
4
1, 1650
-.203*
-.052*
.019
Mating effort factor
5
1, 1650
.243*
.280*
.316*
Sociosexual unrestriction
6 (a)
1, 1648
-.079*
-.020
.013
Slow life history strategy
6 (b)
1, 1095
.043
.060*
.058*
Commitment to the relationship
6 (c)
1, 487
.022
-.010
-.058
Attachment avoidance
6 (d)
1, 1095
.048
.096*
.072*
Attachment anxiety
6 (e)
1, 1095
.294*
.211*
.139*
Satisfaction with the relationship
6 (f)
1, 487
-.194*
-.127*
-.113*
Difference in mate value
6 (g)
1, 1471
.060*
.134*
.095*
Mate value – self
7 (g)
1, 1471
-.116*
-.070*
-.038
Mate value – sexual partner
8 (g)
1, 1471
-.051*
-.007
-.014
Note. * p<.05. Order reflects the position of each predictor in the hierarchical GLMs, with
different letters indicating predictors that were entered in alternative, separate analyses as they
were on an equivalent level of data aggregation. Major historical and economic group compares
the scores of the North-American and Norwegian samples against those of the Brazilian sample. In
Continent, the Norwegian sample is compared to North-American samples. In Region, the
Midwestern-American sample is compared to the Anglo-American sample. Sex compares the
males’ scores on NPE factors to those of women.
Attachment anxiety positively predicted the frequency of all three NPE factors beyond the
effects of mating effort, with stronger effects on the neediness NPE factor than on the avoidance
NPE factor (Fisher’s z
=
3.82, p
<
.05) in line with Hypothesis VII. Satisfaction with the
relationship negatively predicted all three NPE factors beyond the effects of mating effort,
supporting Hypothesis VIII. The perceived difference in mate value between the participants
and their partners was a positive predictor of the frequency of all NPE factors beyond mating effort,
and this effect was strongest on the reputation-maintenance NPE factor and weakest on the
neediness NPE factor, in line with Hypothesis IX (note, however, that these effects were weak),
with a significant difference between the predictive power of that independent variable upon these
two NPE factors (Fisher’s z
=
2.03, p
<
.05). Self-rated mate value and the perceived mate value
of one’s partner negatively explained additional variance in part of the NPE factors, but these effects
were weak, as predicted in Hypothesis IX.
All NPE factors were more frequently experienced by participants from the North-American than
by those from the Norwegian sample, the neediness NPE factor was more frequent in the Brazilian
than in other samples, and the avoidance NPE factor was more frequent in the Midwestern-
American than in the broader Anglo-American sample. As expected, the neediness NPE factor
was more commonly experienced by women than men, as can also be observed in Figure 1,
whereas the avoidance NPE factor was only slightly, but nonsignificantly, more frequent in men
than in women.
Also with regard to the frequency of NPE
factors, some significant (p
<
.05) interactions
were detected between the continuous variables
and the variables categorizing the samples by
geography and culture, explaining additional
variance of the frequency of NPE factors beyond
the main effects reported in Table 3. The
interaction terms were entered in the GLMs
after the
main effects reported above. The expected positive effect of the mating effort factor
upon the NPE
factors was weaker in the Norwegian than in the North-American samples (semipartial r
=
-
.068 for
the neediness NPE factor,
-.054 for the reputation-maintenance NPE factor, and -.085 for the
avoidance NPE factor), and weaker in the Midwestern-American than in the Anglo-American
sample for the avoidance NPE factor (semipartial r
=
-.051). Slow life history speed predicted the
reputation-maintenance NPE factor more positively in the North-American and Norwegian
samples than in the Brazilian sample (semipartial r
=
.058). Commitment to relationship predicted
the neediness and the reputation-maintenance NPE factors more positively in the North-American
and Norwegian samples than in the Brazilian sample (semipartial r
=
.147 for the neediness NPE
factor; .106 for the reputation-maintenance NPE factor). Finally, one’s perceived mate value
predicted the neediness NPE factor more positively in the Norwegian than in the North-American
samples (semipartial r
=
.061).
The only continuous variable that significantly (p
<
.05) interacted with sex was the
mating effort factor, with the expected positive
effect of this later predictor upon NPE factors
stronger for women than for men (semipartial
r
=
-
.092 for the neediness NPE factor,
-
.095
for
the reputation-maintenance NPE factor, and
-
063 for the avoidance NPE factor).
Table 4 displays the results of GLMs with the intensity of the NPE factors as outcome variables.
Overall these results were highly similar to the patterns observed with the frequencies of the NPE
factors. In Hypothesis V we predicted that men and women would present similar patterns of activation
in the maintenance of reputation factor, however women reported higher intensity of the reputation-
maintenance NPE factor than men, even though this effect was considerably small in magnitude.
Again the effects of the mating effort factor and the residual effects of attachment anxiety were
the strongest. In line with Hypothesis VI, mating effort was positively related to all NPE factors,
and this relationship was strongest for the avoidance NPE factor, supporting Hypothesis VII. Also
line with this hypothesis, residual attachment anxiety better predicted the neediness NPE factor
than other factors (Fisher’s z
=
2.12, p
<
.05 compared with the effects of attachment anxiety
on the intensity of the reputation-maintenance NPE factor; Fisher’s z
=
4.39, p
<
.05 compared
with the effects on the intensity of the avoidance NPE factor). Sociosexual unrestriction presented
a negative and significant association with the neediness NPE factor beyond the effects of mating
effort again, and paradoxically commitment to one’s relationship was positively associated with
the avoidance NPE factor beyond the effects of mating effort; the residual effects of components of
mating effort upon NPE factors were weak however, in line with Hypothesis VI. Relationship
satisfaction negatively predicted the neediness and the reputation-maintenance NPE factors, but
not the avoidance NPE factor, thus partially supporting Hypothesis VIII. Self-rated mate value but
not partner mate value negatively explained additional variance in part of the NPE factors, and
these significant effects were weak, lending partial support to Hypothesis IX.
Table 4. Semipartial correlations from hierarchical general linear models predicting the intensity
of NPE factors
Predictor
Order
NDF,
DDF
Semipartial correlation
Need for
bonding
Maintenance
of reputation
Avoidance
of bonding
Major historical/economic group
1
1, 1528
-.159*
-.028
-.131*
Continent
2
1, 1528
-.082*
-.071*
-.014
Region
3
1, 1528
-.064*
.018
-.031
Sex
4
1, 1528
-.207*
-.053*
-.013
Mating effort factor
5
1, 1528
.211*
.246*
.274*
Sociosexual unrestriction
6 (a)
1, 1526
-.057*
-.010
.009
Slow life history strategy
6 (b)
1, 1035
-.021
.021
.009
Commitment to relationship
6 (c)
1, 466
.049
.011
.130*
Attachment avoidance
6 (d)
1, 1035
.003
.046
.016
Attachment anxiety
6 (e)
1, 1035
.296*
.209*
.112*
Satisfaction with relationship
6 (f)
1, 466
-.103
-.101
-.023
Difference in mate value
6 (g)
1, 1397
.093*
.143*
.101*
Mate value – self
7 (g)
1, 1397
-.112*
-.082*
-.074*
Mate value – sexual partner
8 (g)
1, 1397
.001
.021
.008
Note. * p<.05. Order reflects the position of each predictor in the hierarchical GLMs, with
different letters indicating predictors that were entered in alternative, separate analyses as they
were on an equivalent level of data aggregation. Major historical and economic group compares
the scores of the North-American and Norwegian samples against those of the Brazilian sample. In
Continent, the Norwegian sample is compared to North-American samples. In Region, the
Midwestern-American sample is compared to the Anglo-American sample. Sex compares the
males’ scores on NPE factors to those of women.
The neediness and the reputation-maintenance NPE factors were more intensely experienced by
participants from the North-American than by those from the Norwegian sample, the neediness
and the avoidance NPE factors were more intense in the Brazilian than in other samples, and the
neediness NPE factor was more intense in the broader Anglo-American than in the Midwestern-
American sample. As expected, the neediness NPE factor was more intensely experienced by
women than men, but as can also be observed in Figure 1, whereas the difference in the intensity
of the avoidance NPE factor between men and women was negligible and not statistically
significant.
Just as observed with the frequency of NPEs, with regard to the intensity of NPE factors, some
significant (p
<
.05) interactions were detected between the continuous variables and the variables
categorizing the samples by geography and culture, explaining additional variance of the
intensity of NPE factors beyond the main effects reported in Table 4. However these
interactions were fewer in number than those detected with the frequency of NPE factors are
outcome variables. The expected positive effect of the mating effort factor on the avoidance NPE
factor was weaker in Norwegian and North-American samples than in the Brazilian one
(semipartial r
=
-.089), and weaker in the Norwegian than in the North-American samples
(semipartial r
=
-.065). The effect of relationship commitment on the neediness NPE factor was
stronger in Norwegian and North-American samples than in the Brazilian one (semipartial r
=
.125). One’s own perceived mate value predicted all three NPE factors less negatively in the
Norwegian than in the North-American samples (semipartial r
=
.094 for the neediness NPE
factor, .075 for the reputation-maintenance NPE factor, and .093 for the avoidance NPE factor).
Also as observed with the frequency of NPEs, few interactions with sex were detected when
predicting the intensity of NPE factors. The expected positive effect of the mating effort factor on
the neediness and reputation-maintenance NPE factors was stronger for men than for women
(semipartial r
=
.070 for the neediness NPE factor, and .059 for the reputation-maintenance NPE
factor). As interactions between mating effort and sex were identified both when predicting the
frequency and the intensity of NPEs, we ran a post hoc analysis to assess whether men and women
had different variances in mating effort, as range restriction is known to be an important factor
in the attenuation of correlations (Hunter & Schmidt, 2004). Levene’s test for equality of
variances indicated that indeed men presented a larger variance in mating effort scores than
women, F(2, 1656)
=
3.58, and this was borderline significant (p
=
.05).
Prevalence of NPEs
As an exploratory assessment of the overall frequencies of NPEs across samples and sexes,
Table 5 displays the percentage of participants who have never, rarely, sometimes, often, and all
the time experienced at least one negative emotion after intercourse. Note that these estimates
do not refer to the mean frequency with which participants have experienced all of the negative
emotions assessed, but are rather based on the NPE or NPEs with the highest frequency reported by
each participant. Mean frequencies for each factor of NPEs are examined and compared in analyses
presented above.
Table 5. Percentages of participants by sample and sex who reported having never, rarely,
sometimes, often, or all the time experienced one or more of the twenty-three negative post-coital
emotions assessed.
Sample and Sex
Percentage of participants who have experienced one or more NPEs
Never
Rarely
Sometimes
Often
All the time
Brazilian
Males
16.08
15.38
44.76
19.58
4.20
Females
11.25
16.25
42.19
22.50
7.81
Midswestern-American
Males
17.50
26.67
39.17
10.83
5.83
Females
11.26
22.51
40.26
20.35
5.63
Anglo-American
Males
20.69
18.39
34.48
13.79
12.64
Females
11.61
14.98
32.58
26.97
13.86
Norwergian
Males
16.31
29.08
43.26
10.64
.71
Females
13.56
27.13
48.40
10.64
.27
Women reported experiencing more recurrent NPEs than men in all samples, and these
effects were significant (p
<
.05) in the Midwestern-American sample, t(349)
=
2.17, Cohen’s
d
=
.24; and in the Anglo-American
sample, t(352)
=
2.48, Cohen’s d
=
.30; but not
in the
Brazilian sample, t(461)
=
1.76, Cohen’s
d
=
.18; or in the Norwegian sample, t(515)
=
.76,
Cohen’s d
=
.07.
Finally, on noticing apparent age differences between the samples we examined this in detail as
post hoc analyses. The age of the participants in the Midwestern-American sample was significantly
(p
<
.05) lower than that in the Brazilian sample, t(827.58)
=
23.20; in the Anglo-American
sample, t(571.22)
=
10.17; and in the Norwegian sample, t(772.22)
=
23.20. Age was higher in the
Brazilian sample than in the Anglo-American sample, t(711.65)
=
7.54; and in the Norwegian
sample, t(868.42)
=
12.98. No significant differences in age were detected between Norwegian
participants and those in the Anglo-American sample, t(542.76)
=
.93.
Discussion
This study provides the first comprehensive examination of the relationships between a large
array of negative postcoital emotions (NPEs) and both Sexual Strategies Theory and the adaptive
importance of social reputation. This is also the first study to investigate the existence of different
groups of NPEs, examining whether data on them are indicative of mechanism failure and
pathology or of predictable adaptive function.
Three dimensions of NPEs seem to exist in all populations studied, with the sets of emotions
comprised in each factor corresponding extremely closely to the three factors that we
hypothesized. Each dimension of NPEs comprises a group of emotions that, together, might have
been selected to deal with adaptive problems hypothesized to have occurred in the postcoital time
interval during the evolutionary history of the human lineage. To test that, we examined
whether each dimension would provide evidences of design features consistent with
evolutionarily-informed hypotheses.
Design Features of the Three Dimensions of NPEs
All three factors of NPEs were more frequent and more intense in individuals of higher mating
effort. This suggests that adaptive problems that posed threats to one’s fitness following sexual
intercourse were more common in individuals who invested more heavily in shortterm sexual
relationships, and NPEs were likely to motivate actions to avoid those threats. Mating effort was
more strongly related to the avoidance NPE factor, intermediately related to the reputation-
maintenance NPE factor, and more weakly to the neediness NPE factor, in line with predictions,
and indicating that the most common NPEs activated in individuals who prioritize short-term
relationships are emotions such as a need to be alone, disgust for one’s partner, irritability,
apathy, anger, and pity, which are frequently experienced in conjunction. This group of emotions
is likely to have motivated and facilitated one’s extraction from unwanted romantic commitments
and prior to heavy investment (see also Haselton & Buss, 2001). The residual effects of the specific
indicators of mating effort upon NPE factors were weak, confirming that they are related to
NPEs mainly through the common factor, and the residual effects were mostly in line with the
effects of the mating effort factor.
Attachment anxiety was the principal predictor of the neediness NPE factor both in the cases of
frequency and intensity, and only a weak predictor of the avoidance NPE factor, also in line
with hypotheses. This suggests that the neediness NPE factor is, to a considerable degree, an
expression of one’s worries about being abandoned by one’s partner and worries that one’s
feelings for a partner are not reciprocated, and is likely to be a mechanism to elicit relationship
commitment and additional investment from romantic partners. In line with this, as expected,
emotions of the neediness NPE factor were frequently linked to a behavioral signal: Tearfulness.
Crying and tears may function as an honest signal of helplessness (Miceli & Castelfranchi, 2003),
informing that one is vulnerable, and eliciting attention, empathy, and support (Hasson, 2009).
However, it was a limitation of this study not to explore whether the emotions that we summarize
under the term ‘need for bonding’ are sometimes intended to elicit empathy and support from
individuals other than one’s sexual partner, perchance sometimes functioning as a need for
bonding and support from family, friends, or other romantic partners.
It was expected that the reputation-maintenance and the avoidance NPE factors would be
positively predicted by the difference in mate value between the participants and their partners,
as committing to partners of lower mate value after short-term liaisons might inflict
costs to
one’s reputation. However these relationships were not strong, even though the difference in mate
value was a stronger positive predictor of frequency and intensity of these two NPE factors
than of the neediness NPE factor. Finally, we also predicted that relationship satisfaction would
be negatively related to the frequency and intensity of all NPE factors, and although this was
corroborated, the magnitude of these associations was small beyond the effects of mating effort. It
should also be noted that, as they are likely to be less temporally stable traits than the others
assessed in thus study (for a comprehensive analysis of the stability of life history and personality
traits, see Figueredo, Cabeza de Baca, & Black, 2014), relationship satisfaction and the perception
one has of one’s partner may be reduced, at least temporarily, after experiencing NPEs,
especially those related to the reputation-maintenance and the avoidance NPE factors. In other
words, it is difficult to confidently interpret the order of causation for the relationship between
these less stable traits and NPEs in the present study.
NPEs of the reputation-maintenance NPE factor shared several design features with the
avoidance NPE factor and with the neediness NPE factor, presenting associations with other
psychological variables that were intermediate in magnitude between those found for the neediness
NPE factor and for the avoidance NPE factor. Even so, it consistently figured as a separate factor
in all samples, with emotions that have traditionally been seen as facilitators of maintenance or
recuperation of social reputation (Fessler, 2004). Some yet unexplored reasons could conceivably
help explain the existence of such a dimension as separate from the other two. For instance,
besides promoting the maintenance of social reputation, the emotions comprised in that factor may
also have served, over evolutionary history, to facilitate reparation and compensation of harm
inflicted on others (Fessler, 2004; Ghorbani, Liao, Çayköylü, & Chand, 2013). In the postcoital
time interval, those emotions perhaps helped to prevent the dissolution of valued relationships,
such as preventing the break-up of a long-term relationship after one has perpetrated sexual
infidelity, or preventing severe punishment after having carried out coercive sexual intercourse.
This possibility is still to be explored.
NPEs were on average more common and more intensely experienced in the Brazilian sample,
and the Norwegian sample presented the smallest frequencies and intensity of NPEs, however
these sample differences were small in magnitude compared the main effects of mating effort and
attachment anxiety. Additionally, only weak interactions were detected between the samples and
the continuous predictors of the NPE factors, with most interactions being nonsignificant,
suggesting that the nomological net of NPEs is highly cross-cultural, in spite of the differences
between the countries studied regarding their biocultural histories, attitudes toward and
conceptualizations of the development of sexual encounters, female acceptance of male sexual
advances, openness to displays of nudity and sexuality, female subordination to men, acceptance
of female sexuality, and overall liberal attitudes toward sexuality (see the Method section).
The only predictor of NPE factors to present significant interactions with sex was mating effort,
suggesting that the frequency and the intensity of NPEs are more strongly related to mating
effort in men than in women. These latter interactions were possibly attributable to the range
restriction identified in women’s mating effort across the samples, as this is known to attenuate the
magnitude of correlations (Hunter & Schmidt, 2004).
Differences in NPEs Between the Sexes
Participant Sex by NPE factor interactions (which are arguably the main test of sex differences;
see Edlund & Sagarin, 2009; Sagarin, 2005; Sagarin et al., 2012) were confirmed in all cultures
both for frequency and intensity of NPEs, indicating that men, relative to women, experience the
avoidance NPE factor more frequently and more intensity than the neediness NPE factor, and
women the reverse. Within-sex simple effects also generated substantial evidence for each of these
types of NPEs being more prominent in one of the sexes. That suggests that sex differences in
NPEs are in line with the main differences in sexual strategies between the sexes (Buss &
Schmitt, 1993), and in accordance with previous findings of several sex differences in the
postcoital time interval (e.g., Campbell, 2008; Haselton & Buss, 2001; Kruger & Hughes, 2010;
Townsend et al., 1995). Both dimensions of NPEs, however, appear to be to some degree
important for both sexes. It should also be noted that a significant,
albeit considerably weak, sex
difference was found for the frequency and intensity of the factor including shame, guilt, self-
disgust, and remorse, with women on average reporting higher scores than men, indicating that,
at least among young adults, threats to sexual reputation are to a small extent more frequent
and intense for females than for males. This suggests that the sexes differ not only in terms of
the reasons for experiencing these emotions (e.g., Galperin et al., 2013; Kennair et al., 2015), but
also in terms of their frequency and intensity, even though the sex differences in this factor of NPEs
are very small.
To our knowledge, this is the fi study to date investigating prevalence of NPEs in men.
Contrary to what had been predicted based on clinical information in the psychiatric literature
(Sadock & Sadock, 2008), men did not report overall higher levels of NPEs than women in
any NPE factor, and actually the opposite was observed for two of the three factors.
Noticeably, the percentages of individuals who reported having already experienced NPEs
in this study (the percentage of men who have already experienced one or more NPEs at least
once was between 79% and 84%, and the frequency was between 86% and 89% among
women, depending on the sample) are much higher than previous estimates (Bird et al., 2011;
Burri & Spector, 2011), which is most likely attributable to our participants having been asked
about a considerably larger number of negative emotions.
Status of NPEs as a Disorder
In accordance with the “harmful dysfunction” analysis of disorder (Kennair, 2003, 2011;
Wakefield, 1999, 2007), we argue that the results of this study lack indications of NPEs being
pathological. Importantly, the present study provides evidences that the dimensions of NPEs are
part of and are likely to facilitate the mode of functioning and the ultimate goals of different
sexual strategies, besides motivating efforts to maintain or regain social reputation. Harmfulness
alone (i.e., suffering) is not a sign of pathology. Additionally, a considerable part of individuals
afflicted with NPEs is not distressed by them (Burri & Spector, 2011), thus NPEs may sometimes
be neither harmful nor evolutionarily dysfunctional. However, we do not imply that all
experiences of NPEs are functional, because in some individuals the threshold for their activation
might be abnormal and maladaptive, or gain settings for NPEs may be upregulated (see Nesse,
2009; Tooby & Cosmides, 1990). That possibility has not yet been explored. Nevertheless, it is
safe to conclude that the results herein presented provide evidence that the capacity to experience
NPEs shows signs of having evolved functions and, consequently, does not show signs of
disorder.
Limitations, Future Directions, and Concluding Remarks
Some limitations qualify the results presented. First, although the Brazilian sample and the
Anglo-American sample were not restricted to students and were nationally broad, participants
from Norway and from the Midwestern-American sample were local students and were young
adults. Therefore, the results may not be largely representative of the cultures of these countries.
Second, given that the we conducted the assessment of levels of NPEs on a 5-point Likert-type
scale, and that sample means centered between 1 and 2 with a relatively small variance, a greater
level of precision would have been possible with the use of more points, and the findings that we
discussed might actually underestimate the magnitude of the sex differences and correlations
between NPEs and other variables.
It is unlikely that the age differences between samples impacted the results importantly: age was
not significantly correlated to any NPE factor when using the frequency of experiences of NPEs
even though the total sample surpassed 1700 participants, and only very weakly predicted the
intensity of the NPE factors related to need for bonding and to avoidance of bonding (r
=
.07 in
both cases; p
<
.05), not significantly predicting the intensity of the NPE factor related to the
maintenance of reputation.
It is important to note that moderate to substantial positive correlations (see Kotrlik & Williams,
2003) were detected between the three NPE factors, as they each share around a third of their
variance with each other factor. It is thus likely that certain postcoital situations may trigger more
than one kind of adaptive problem, each dealt with by different groups of emotions to a certain
degree. Future research should explore which possible scenarios lead to the activation of more than
one, as opposed to a specific, NPE factor.
Our study provides initial cross-cultural evidence of the existence of three groups of negative
postcoital emotions (NPEs), each with specific design features that are largely congruent with
evolutionarily-informed hypotheses. The capacity to experience NPEs appears to have a functional
rather than a dysfunctional basis in sexual strategies and maintenance of sexual reputation, not
being liable to <