ArticlePDF Available

Cues of Being Watched Enhance Cooperation in a Real-World Setting

Authors:

Abstract and Figures

We examined the effect of an image of a pair of eyes on contributions to an honesty box used to collect money for drinks in a university coffee room. People paid nearly three times as much for their drinks when eyes were displayed rather than a control image. This finding provides the first evidence from a naturalistic setting of the importance of cues of being watched, and hence reputational concerns, on human cooperative behaviour.
Content may be subject to copyright.
Biol. Lett. (2006) 2, 412–414
doi:10.1098/rsbl.2006.0509
Published online 27 June 2006
Cues of being watched
enhance cooperation in
a real-world setting
Melissa Bateson
*
, Daniel Nettle
and Gilbert Roberts
Evolution and Behaviour Research Group, School of Biology and
Psychology, University of Newcastle upon Tyne, Henry Wellcome
Building for Neuroecology, Framlington Place, Newcastle upon Tyne
NE2 4HH, UK
*Author for correspondence (melissa.bateson@ncl.ac.uk).
We examined the effect of an image of a pair of
eyes on contributions to an honesty box used to
collect money for drinks in a university coffee
room. People paid nearly three times as much
for their drinks when eyes were displayed rather
than a control image. This finding provides the
first evidence from a naturalistic setting of the
importance of cues of being watched, and hence
reputational concerns, on human cooperative
behaviour.
Keywords: cooperative behaviour; altruism;
reputation; eyespots
1. INTRODUCTION
People tend to be generous, even toward unrelated
individuals (Fehr & Fischbacher 2003). This is true
even in situations where there is no prospect of repeat
interaction, and hence no potential for direct recipro-
city (Gintis et al.2003). A possible mechanism
maintaining generosity, where direct reciprocity is
absent, is the motivation to maintain a pro-social
reputation (Alexander 1987; Roberts 1998).
Theoretical models show that cooperation in sizeable
groups can, in theory, be maintained where potential
partners have information about a person’s past
behaviour and use it in making decisions about intera-
ction (Nowak & Sigmund 1998; Panchanathan &
Boyd 2004). In indirect reciprocity models of this
kind, individuals with a history of non-cooperation
are shunned and thus pay a long-term cost for their
behaviour. Consistent with such models, laboratory
experiments have shown that people increase their
levels of cooperation when they know their behaviour
is being observed by others, and also use reputational
information in deciding how to interact with others
(Milinski et al. 2002a,b; Wedekind & Braithwaite
2002; Barclay 2004).
Recent studies have shown that even when subjects
are told they are anonymous, they respond to subtle
cues of being watched, such as the presence of eye-like
spots on the background of the computer on which they
complete the task (Haley & Fessler 2005; Burnham &
Hare in press). However, these studies were based on
artificial laboratory scenarios, and the effects of such
cues on naturally occurring cooperative behaviour
remain to be demonstrated. Here, we investigate
whether subtle cues of being watched can increase
contributions to a public good in a real-world setting
where people have the option of contributing or not,
using their own money. Specifically, we test the
hypothesis that participants will contribute more money
to an honesty box (also known as an honour box) in the
presence of an image of a pair of eyes than in the
presence of a control image of flowers.
2. MATERIAL AND METHODS
Participants came from a population of 48 members (25 females
and 23 males) of the Division of Psychology at the University of
Newcastle, who had the option to pay for tea and coffee via an
honesty box. This system of payment for drinks had been in place
for several years prior to the commencement of the current study.
Instructions for payment remained constant throughout the experi-
ment, and were posted on a black and white A5-sized (148 mm
high!210 mm wide) notice. The notice was displayed at eye height
on a cupboard door located above a counter on which was situated
the honesty box and also the coffee and tea making equipment; the
fridge containing the milk was below the same counter. The notice
featured a 150!35 mm banner that alternated each week between
an image of a pair of eyes and an image of flowers printed above
the prices for tea, coffee and milk (30, 50 and 10 pence,
respectively). A different image was used each week to control for
any effects attributable to a single image. The images of eyes varied
in the sex and head orientation, but were all chosen such that the
eyes were looking directly at the observer. In addition to the notice,
all members of the department were informed by email approxi-
mately every six months about the arrangements for payment for
tea and coffee; the most recent reminder was sent approximately
one month prior to the commencement of this study. From the
perspective of the participants, the only change introduced at the
start of the experiment was the inclusion of the image banner on
the notice. Participants were naive to the purposes of the manipu-
lation and none reported being aware of these. The layout of the
coffee room is such that it is unlikely that anyone failing to pay
would be observed. Hence, contributions were effectively anon-
ymous, and participants could choose whether and how much to
pay for their drinks.
Each week we recorded the total amount of money collected in
the honesty box. Throughout the period of the study, supplies of
tea, coffee and milk were maintained to keep up with demand, and
each week, the volume of milk consumed was recorded as the best
index available of total beverage consumption. We computed the
ratio of money collected to the volume of milk consumed in each
week to control for weekly variation in consumption.
3. RESULTS
The ratio of money collected to milk consumed for
each of the 10 weeks is shown in figure 1, along with
the image on the banner for that week. Contribution
levels always increased with the transition from
flowers to eyes, and decreased with the transition
from eyes to flowers. A general linear model with
factors image type (fixed) and week (covariate) fitted
to log-transformed data explained 63.8% of the
variance. There was a significant main effect of image
type (eyes versus flowers: F
1,7
Z11.551, pZ0.011)
but not week (F
1,7
Z 0.074, p Z 0.794). The
interaction between image type and week was omitted
from the model because it was not significant. On
average, people paid 2.76 times as much in the weeks
with eyes (meanGs.e.Z0.417G0.081 £ per litre) than
with flowers (0.151G0.030 £ per litre). There was no
evidence that image type affected consumption.
4. DISCUSSION
Our results show that an image of a pair of eyes
appearing to observe behaviour dramatically increases
contribution to a public good in a real-world context
where participants were behaving naturally and using
their own money.
Received 14 April 2006
Accepted 2 June 2006
412 q 2006 The Royal Society
Why does an image of a pair of eyes motivate
cooperative behaviour? While it is possible that the
eyes were simply more effective than the flowers at
attracting people’s attention to the notice, we do not
believe that this is the explanation for our findings.
The participants had all been informed prior to the
experiment that they were supposed to pay for their
drinks. Furthermore, the notice was positioned such
that it was not possible that anyone making drinks
would fail to see it, irrespective of the image
displayed.
Instead, we believe that images of eyes motivate
cooperative behaviour because they induce a percep-
tion in participants of being watched. Although
participants were not actually observed in either of
our experimental conditions, the human perceptual
system contains neurons that respond selectively to
stimuli involving faces and eyes (Emery 2000; Haxby
et al. 2000), and it is therefore possible that the
images exerted an automatic and unconscious effect
on the participants’ perception that they were being
watched. Our results therefore support the hypothesis
that reputational concerns may be extremely powerful
in motivating cooperative behaviour.
Our findings have practical interest for those
designing honesty-based systems, or wishing to maxi-
mize contributions to public goods. They also have
theoretical implications. Faced with the relative gen-
erosity of human cooperation, even when interactions
are explicitly anonymous and not repeated, some
scholars have argued that humans are not always
maximizers of individual self-interest (Camerer &
Fehr 2006), but instead have been shaped to be
pro-social or other-regarding by a history of group
selection (Gintis 2000; Gintis et al. 2003). A simpler
explanation is simply that humans are strongly
attuned to cues that generally indicate reputational
consequences of behaviour (Burnham & Johnson
2005; Haley & Fessler 2005). If even very weak,
subconscious cues, such as the photocopied eyes used
in this experiment, can strongly enhance cooperation,
it is quite possible that the cooperativeness observed
in other studies results from the presence in the
experimental environment of subtle cues evoking the
psychology of being observed. The power of these
subconscious cues may be sufficient to override the
explicit instructions of the experimenter to the effect
that behaviour is anonymous. If this interpretation is
correct, then the self-interested motive of reputation
maintenance may be sufficient to explain cooperation
in the absence of direct return.
M.B. is funded by a Royal Society University Research
Fellowship. We thank T. Burnham for sending us his
unpublished manuscripts.
Alexander, R. D. 1987 The biology of moral systems.NewYork,
NY: Aldine de Gruyter.
Barclay, P. 2004 Trustworthiness and competitive altruism
can also solve the “tragedy of the commons”. Evol. Hum.
Behav. 25, 209–220. (doi:10.1016/j.evolhumbehav.2004.
04.002)
Burnham, T. & Hare, B. In press. Engineering human
cooperation: does involuntary neural activation increase
public goods contributions? Hum. Nat.
Burnham, T. & Johnson, D. D. P. 2005 The evolutionary
and biological logic of human cooperation. Analyse Kritik
27, 113–135.
£
p
aid
p
er litre of milk consumed
image
8
6
4
2
7
5
3
1
time
(weeks)
eye weeks
flower weeks
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7
9
10
Figure 1. Pounds paid per litre of milk consumed as a function of week and image type.
Eyes promote cooperation M. Bateson and others 413
Biol. Lett. (2006)
Camerer, C. F. & Fehr, E. 2006 When does ‘economic
man’ dominate social behaviour? Science 311, 47.
(doi:10.1126/science.1110600)
Emery, N. J. 2000 The eyes have it: the neuroethology,
function and evolution of social gaze. Neurosci. Biobehav.
Rev. 24,581604.(doi:10.1016/S0149-7634(00)00025-7)
Fehr, E. & Fischbacher, E. 2003 The nature of human
altruism. Nature 425, 785. (doi:10.1038/nature02043)
Gintis, H. 2000 Strong reciprocity and human sociality.
J. Theor. Biol. 206,169179.(doi:10.1006/jtbi.2000.2111)
Gintis, H., Bowles, S., Boyd, R. & Fehr, E. 2003 Explaining
altruistic behavior in humans. Evol. Hum. Behav. 24,
153–172. (doi:10.1016/S1090-5138(02)00157-5)
Haley, K. J. & Fessler, D. M. T. 2005 Nobody’s watching?
Subtle cues affect generosity in an anonymous economic
game. Evol. Hum. Behav. 26, 245–256. (doi:10.1016/
j.evolhumbehav.2005.01.002)
Haxby, J. V., Hoffman, E. A. & Gobbini, M. I. 2000 The
distributed human neural system for face perception.
Trends Cogn. Sci. 4,223233.(doi:10.1016/S1364-6613
(00)01482-0)
Milinski, M., Semmann, D. & Krambeck, H. J. 2002a
Donors to charity gain in both indirect reciprocity and
political reputation. Proc. R. Soc. B 269, 881–883.
(doi:10.1098/rspb.2002.1964)
Milinski, M., Semmann, D. & Krambeck, H. J. 2002b
Reputation helps solve the ‘tragedy of the commons’.
Nature 415, 424–426. (doi:10.1038/415424a)
Nowak, M. A. & Sigmund, K. 1998 Evolution of indirect
reciprocity by image scoring. Nature 393, 573–577.
(doi:10.1038/31225)
Panchanathan, K. & Boyd, R. 2004 Indirect reciprocity
can stabilize cooperation without the second-order
free rider problem. Nature 432, 499–502. (doi:10.1038/
nature02978)
Roberts, G. 1998 Competitive altruism: from reciprocity to
the handicap principle. Proc. R. Soc. B 265, 427. (doi:10.
1098/rspb.1998.0312)
Wedekind, C. & Braithwaite, V. A. 2002 The long-term
benefits of human generosity in indirect reciprocity.
Curr. Biol. 12, 1012–1015. (doi:10.1016/S0960-9822(02)
00890-4)
414 M. Bateson and others Eyes promote cooperation
Biol. Lett. (2006)
... A variety of experiments report that images of eyes do change the behavior of humans. People give more in a dictator game (Burnham, 2003), give more in a public goods game (Burnham & Hare, 2007), are more likely to pay for their coffee in an 'honor pot' (Bateson et al., 2006), pick up litter (Bateson et al., 2013), and, in Newcastle, steal fewer bicycles from bike racks that are being 'watched' (Nettle et al., 2012). ...
Article
Neoclassical economics assumes that people care only about themselves and, consequently, argues that people will not incur unrepaid costs to harm or help other people. In contrast, behavioral economics documents that people sometimes incur costs to hurt other people (‘apparent spite’) and in other situations incur costs to help others (‘apparent altruism’). Biology argues that, in ancestral settings, such costly acts towards others were adaptive, and arose by natural selection because of benefits redounding to the selfish genes responsible for the behaviors. In evolutionarily novel settings such as cities, however, people will often incur costs that are not repaid. Ordinary: “With no special or distinctive features; normal. Not interesting or exceptional; commonplace.” -Oxford English dictionary.
... While there is mixed experimental evidence regarding the degree to which the feeling of being watched by artificial observers alters cooperative behavior (Bateson et al., 2006;Haley & Fessler, 2005;Krátký et al., 2016;Nettle et al., 2013;Northover et al., 2017aNorthover et al., , 2017bRaihani & Bshary, 2012), some experiments suggest that when children (Piazza et al., 2011) and adults (Bering et al., 2005;Hadnes & Schumacher, 2012;Lang et al., 2019;McNamara et al., 2016;Shariff & Norenzayan, 2007, 2011Yilmaz & Bahçekapili, 2016) are primed with concepts of spiritual beings, they tend to break fewer rules and engage in more equitable behavior. Cross-national studies using aggregate, group-level data also suggest that this is the case (Atkinson & Bourrat, 2011;Stark, 2001). ...
... Thus, it appears that the cleanliness of the work environment may positively influence the propensity to condemn/accept immoral behavior. (Kahneman, 2012) Reminder of mortality It leads to authoritarian values (Greenberg et al., 1990) Thinking about an act he's ashamed of It leads more often to the addition of English words W_ _H and S _ _P to WASH and SOAP instead of WISH and SOUP (Kahneman, 2012) Photo of eyes above the coffee machine where the coffee is based on voluntary payment Leads to higher coffee collections (see image below the table) (Bateson, Nettle and Roberts, 2006) The thought of an individual sticking a dagger in his colleague's back Leads to a tendency to buy more soap, disinfectants versus juice or chocolate (the so-called Lady Macbeth Effect) (Zhong and Liljenquist, 2006) 1 Voters voting in the polling stations at school ...
Article
Full-text available
This paper deals with the issue of psychological factors that influence consumer behaviour and therefore have an impact on demand formation. The paper summarizes existing research studies in the field of social psychology and places these studies in the context of economics, consumer decision making. The paper also highlights the founder of the Bata company, Tomas Bata, who built a multinational shoe company in the 1920s and who intuitively applied rules in the management system for which psychologists only found a scientific explanation in the second half of the 20th century and which did not fully develop into behavioral economics and neuroleadership until the first two decades of the 21st century, 100 years later.
... Reddish, Tok, & Kundt, 2015). Moreover, as a variety of experimental treatments have shown, when people are exposed to indices of agency (e.g., two eyes on a computer screen or a picture of another person), they are more generous and less prone to engage in self-serving behavior (Bateson, Nettle, & Roberts, 2006;Fehr & Schneider, 2010;Haley & Fessler, 2005;Nettle et al., 2013). This suggests that under certain conditions, social regulatory systems engage upon the detection of other minds (Krátký, McGraw, Xygalatas, Mitkidis, & Reddish, 2016;Raihani & Bshary, 2012;Vogt, Efferson, Berger, & Fehr, 2015). ...
... Although employees are sensitive to being observed and want to demonstrate their competence when under surveillance (Ayal et al., 2015;Bateson et al., 2006;Bhave, 2014;Pierce et al., 2015), our research suggests that certain forms of monitoring may not have universally positive effects because of the potential relational consequences. LMSX is critical to an employee's sustained productivity (Dulebohn et al., 2012), which is why monitoring can have a crippling effect on employee, unit, and, ultimately, organizational productivity. ...
Article
Changing workplace dynamics have led employers to increasingly adopt electronic monitoring technologies so supervisors can observe and ensure employee compliance and productivity—outcomes the monitoring literature has long supported. Yet, employee productivity depends on strong leader–member social exchange, and the relational consequences of electronic monitoring for supervisor and employee are not well understood. To help resolve this tension within the monitoring literature and add understanding in regard to the effects of electronic monitoring on employee productivity, we use social exchange theory to examine the implications of electronic monitoring for the supervisor–employee exchange relationship. We theorize that electronic monitoring facilitates (rather than inhibits) production deviance and inhibits (rather than facilitates) task performance by undermining the exchange of social benefits and, consequently, eroding leader–member social exchange. Yet, we also hypothesize that supervisors who give performance monitoring data back to employees in a developmental way (i.e., developmental feedback) compensate for the loss of certain social benefits, and, thereby, buffer the negative relational consequences of electronic monitoring. Across an experimental online study and a field study, we find converging support for our predictions and rule out alternative explanations. This research provides timely insights into how to effectively use electronic monitoring without promoting unintended consequences.
Article
Full-text available
Ethical positions shape within life experiences via confronting and resolving ethical dilemmas of moral issues, and were consisted of idealism and relativism. Within cultural context, Western cultures had low scores on both idealism and relativism (exceptionists) while Eastern ones had high relativism scores with both high idealism (situationists) and low idealism (subjectivists) scores on Ethical Position Questionnaire. Recently, a combination of ethical decision making and awareness started to be investigated under the roof of ethical mindfulness while enabling ethical clinical practices and implementation. Prior to stepping into that area, more explanatory presentation of the relationship between ethical decision making process and mindfulness among prospective psychological health professionals, psychological counseling students were presented in this descriptive study. Results of preliminary analyses showed that approximately half of the participants (39.85 %) are on the situationist side on ethical decision making. As a result of main analyses, it was found that level of mindfulness is related with high scores on both idealism (Mlow=3.90, Mmiddle=4.02, Mhigh=4.26) and relativism (Mlow=3.34, Mmiddle=3.75, Mhigh=4.08).
Article
Interactionism holds that explanatory and interpretive projects are mutually enriching. If so, then the evolutionary and cognitive science of religions’ explanatory theories should aid interpretive projects concerning religious meaning. Although interpretive accounts typically focus on the local and the particular, interpreters over the past century have construed Freud and Marx as offering general interpretive theories. So, precedent for general interpretive theorizing exists. 4E cognitive science, which champions how cognition is embedded in natural and cultural settings, extended into external structures, enacted via motor routines, and embodied via representations rooted in human bodily form, has encouraged interpretive researchers. Theories of embodied cognition especially have embraced a sweeping view of meaning that attends to the emotions’ role and to their evolutionary origins. That inspires a 6E cognitive science that attends to the emotional and evolved dimensions of cognition too and opens up the possibility of general interpretive theories of broadly Darwinian character. Evolved cognitive systems qualify as maturationally natural cognition, which exhibits a distinctive constellation of features. The by-product theory holds that religious representations’ engagement of maturationally natural cognition fosters religions’ success. Representations with some minimal violation of intuitive expectations concerning some ontological category grab attention, stick in memory, and preserve the many automatic inferences accompanying the category. The empirical evidence for this and other elaborations of the by-product view suggests that it discloses dynamics of evolved cognition and associated emotions that tend to guide the pursuit of religious meanings systematically toward well-worn grooves in the semantic landscape.
Article
Full-text available
Human behavior is influenced by the presence of others, which scientists also call ‘the audience effect’. The use of social control to produce more cooperative behaviors may positively influence road use and safety. This study uses an online questionnaire to test how eyes images affect the behavior of pedestrians when crossing a road. Different eyes images of men, women and a child with different facial expressions -neutral, friendly and angry- were presented to participants who were asked what they would feel by looking at these images before crossing a signalized road. Participants completed a questionnaire of 20 questions about pedestrian behaviors (PBQ). The questionnaire was received by 1,447 French participants, 610 of whom answered the entire questionnaire. Seventy-one percent of participants were women, and the mean age was 35 ± 14 years. Eye images give individuals the feeling they are being observed at 33%, feared at 5% and surprised at 26%, and thus seem to indicate mixed results about avoiding crossing at the red light. The expressions shown in the eyes are also an important factor: feelings of being observed increased by about 10-15% whilst feelings of being scared or inhibited increased by about 5% as the expression changed from neutral to friendly to angry. No link was found between the results of our questionnaire and those of the Pedestrian Behavior Questionnaire (PBQ). This study shows that the use of eye images could reduce illegal crossings by pedestrians, and is thus of key interest as a practical road safety tool. However, the effect is limited and how to increase this nudge effect needs further consideration.
Article
Full-text available
Models indicate that opportunities for reputation formation can play an important role in sustaining cooperation and prosocial behavior. Results from experimental economic games support this conclusion, as manipulating reputational opportunities affects prosocial behavior. Noting that some prosocial behavior remains even in anonymous noniterated games, some investigators argue that humans possess a propensity for prosociality independent of reputation management. However, decision-making processes often employ both explicit propositional knowledge and intuitive or affective judgments elicited by tacit cues. Manipulating game parameters alters explicit information employed in overt strategizing but leaves intact cues that may affect intuitive judgments relevant to reputation formation. To explore how subtle cues of observability impact prosocial behavior, we conducted five dictator games, manipulating both auditory cues of the presence of others (via the use of sound-deadening earmuffs) and visual cues (via the presentation of stylized eyespots). Although earmuffs appeared to reduce generosity, this effect was not significant. However, as predicted, eyespots substantially increased generosity, despite no differences in actual anonymity; when using a computer displaying eyespots, almost twice as many participants gave money to their partners compared with the controls. Investigations of prosocial behavior must consider both overt information about game parameters and subtle cues influencing intuitive judgments.
Article
Full-text available
Human cooperation is held to be an evolutionary puzzle because people voluntarily engage in costly cooperation, and costly punishment of non-cooperators, even among anonymous strangers they will never meet again. The costs of such cooperation cannot be recovered through kin-selection, reciprocal altruism, indirect reciprocity, or costly signaling. A number of recent authors label this behavior ‘strong reciprocity’, and argue that it is: (a) a newly documented aspect of human nature, (b) adaptive, and (c) evolved by group selection. We argue exactly the opposite; that the phenomenon is: (a) not new, (b) maladaptive, and (c) evolved by individual selection. In our perspective, the apparent puzzle disappears to reveal a biological and evolutionary logic to human cooperation. Group selection may play a role in theory, but it is neither necessary nor sufficient to explain human cooperation. Our alternative solution is simpler, makes fewer assumptions, and is more parsimonious with the empirical data.
Article
Full-text available
Recent experimental research has revealed forms of human behavior involving interaction among unrelated individuals that have proven difficult to explain in terms of kin or reciprocal altruism. One such trait, strong reciprocity is a predisposition to cooperate with others and to punish those who violate the norms of cooperation, at personal cost, even when it is implausible to expect that these costs will be repaid. We present evidence supporting strong reciprocity as a schema for predicting and understanding altruism in humans. We show that under conditions plausibly characteristic of the early stages of human evolution, a small number of strong reciprocators could invade a population of self-regarding types, and strong reciprocity is an evolutionary stable strategy. Although most of the evidence we report is based on behavioral experiments, the same behaviors are regularly described in everyday life, for example, in wage setting by firms, tax compliance, and cooperation in the protection of local environmental public goods.
Article
Full-text available
Current work on cooperation is focused on the theory of reciprocal altruism. However, reciprocity is just one way of getting a return on an investment in altruism and is difficult to apply to many examples. Reciprocity theory addresses how animals respond dynamically to others so as to cooperate without being exploited. I discuss how introducing differences in individual generosity together with partner choice into models of reciprocity can lead to an escalation in altruistic behaviour. Individuals may compete for the most altruistic partners and non-altruists may become ostracized. I refer to this phenomenon as competitive altruism and propose that it can represent a move away from the dynamic responsiveness of reciprocity. Altruism may be rewarded in kind, but rewards may be indirectly accrued or may not involve the return of altruism at all, for example if altruists tend to be chosen as mates. This variety makes the idea of competitive altruism relevant to behaviours which cannot be explained by reciprocity. I consider whether altruism might act as a signal of quality, as proposed by the handicap principle. I suggest that altruistic acts could make particularly effective signals because of the inherent benefits to receivers. I consider how reciprocity and competitive altruism are related and how they may be distinguished.
Article
Full-text available
Darwinian evolution has to provide an explanation for cooperative behaviour. Theories of cooperation are based on kin selection (dependent on genetic relatedness), group selection and reciprocal altruism. The idea of reciprocal altruism usually involves direct reciprocity: repeated encounters between the same individuals allow for the return of an altruistic act by the recipient. Here we present a new theoretical framework, which is based on indirect reciprocity and does not require the same two individuals ever to meet again. Individual selection can nevertheless favour cooperative strategies directed towards recipients that have helped others in the past. Cooperation pays because it confers the image of a valuable community member to the cooperating individual. We present computer simulations and analytic models that specify the conditions required for evolutionary stability of indirect reciprocity. We show that the probability of knowing the 'image' of the recipient must exceed the cost-to-benefit ratio of the altruistic act. We propose that the emergence of indirect reciprocity was a decisive step for the evolution of human societies.
Article
Full-text available
Face perception, perhaps the most highly developed visual skill in humans, is mediated by a distributed neural system in humans that is comprised of multiple, bilateral regions. We propose a model for the organization of this system that emphasizes a distinction between the representation of invariant and changeable aspects of faces. The representation of invariant aspects of faces underlies the recognition of individuals, whereas the representation of changeable aspects of faces, such as eye gaze, expression, and lip movement, underlies the perception of information that facilitates social communication. The model is also hierarchical insofar as it is divided into a core system and an extended system. The core system is comprised of occipitotemporal regions in extrastriate visual cortex that mediate the visual analysis of faces. In the core system, the representation of invariant aspects is mediated more by the face-responsive region in the fusiform gyrus, whereas the representation of changeable aspects is mediated more by the face-responsive region in the superior temporal sulcus. The extended system is comprised of regions from neural systems for other cognitive functions that can be recruited to act in concert with the regions in the core system to extract meaning from faces.
Article
The benefits of a good reputation can help explain why some individuals are willing to be altruistic in situations where they will not receive direct benefits. Recent experiments on indirect reciprocity have shown that when people stand to benefit from having a good reputation, they are more altruistic towards groups and charities. However, it is unknown whether indirect reciprocity is the only thing that can cause such an effect. Individuals may be altruistic because it will make them more trustworthy. In this study, I show that participants in a cooperative group game contribute more to their group when they expect to play a dyadic trust game afterwards, and that participants do tend to trust altruistic individuals more than nonaltruistic individuals. I also included a condition where participants had to choose only one person to trust (instead of being able to trust all players) in the dyadic trust game that followed the cooperative group game, and contributions towards the group were maintained best in this condition. This provides some evidence that competition for scarce reputational benefits can help maintain cooperative behaviour because of competitive altruism.
Article
Gaze is an important component of social interaction. The function, evolution and neurobiology of gaze processing are therefore of interest to a number of researchers. This review discusses the evolutionary role of social gaze in vertebrates (focusing on primates), and a hypothesis that this role has changed substantially for primates compared to other animals. This change may have been driven by morphological changes to the face and eyes of primates, limitations in the facial anatomy of other vertebrates, changes in the ecology of the environment in which primates live, and a necessity to communicate information about the environment, emotional and mental states. The eyes represent different levels of signal value depending on the status, disposition and emotional state of the sender and receiver of such signals. There are regions in the monkey and human brain which contain neurons that respond selectively to faces, bodies and eye gaze. The ability to follow another individual's gaze direction is affected in individuals with autism and other psychopathological disorders, and after particular localized brain lesions. The hypothesis that gaze following is "hard-wired" in the brain, and may be localized within a circuit linking the superior temporal sulcus, amygdala and orbitofrontal cortex is discussed.