Evolutionary Psychology

Sex differences in risk taking behavior among Dutch cyclists

Tue, 14 May 2013 01:51:28 +0000

By Cobey, K. D., Stulp, G., Laan, F., Buunk, A. P., Pollet, T. V.

The majority of research examining sex differences in risk-taking behavior focuses on overt physical risk measures in which failed risk attempts may result in serious injury or death. The present research describes sex differences in patterns of risk taking in day-to-day behavior among Dutch cyclists. Through three observational studies we test sex differences in risk taking in situations of financial risk (fines for failing to use bike lights, Study 1), theft risk (bike locking behavior, Study 2) as well as physical risk (risky maneuvers, Study 3). Results corroborate previous findings by showing that across these domains men are more inclined to take risks than women. We discuss how these findings might be used in an applied context.

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Coming of age in the evolutionary behavioral sciences: A review of Nicholas B. Davies, John R. Krebs, and Stuart A. West, An Introduction to Behavioural Ecology, 4th Edition

Tue, 30 Apr 2013 15:27:51 +0000

By Barrett, H. C.

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Collective action and the detrimental side of punishment

Fri, 12 Apr 2013 04:52:33 +0000

By Shutters, S. T.

Cooperative behavior is the subject of intense study in a wide range of scientific fields, yet its evolutionary origins remain largely unexplained. A leading explanation of cooperation is the mechanism of altruistic punishment, where individuals pay to punish others but receive no material benefit in return. Experiments have shown such punishment can induce cooperative outcomes in social dilemmas, though sometimes at the cost of reduced social welfare. However, experiments typically examine the effects of punishing low contributors without allowing others in the environment to respond. Thus, the full ramifications of punishment may not be well understood. Here, I use evolutionary simulations of agents playing a continuous prisoners dilemma to study behavior subsequent to an act of punishment, and how that subsequent behavior affects the efficiency of payoffs. Different network configurations are used to better understand the relative effects of social structure and individual strategies. Results show that when agents can either retaliate against their punisher, or punish those who ignore cheaters, the cooperative effects of punishment are reduced or eliminated. The magnitude of this effect is dependent on the density of the network in which the population is embedded. Overall, results suggest that a better understanding of the aftereffects of punishment is needed to assess the relationship between punishment and cooperative outcomes.

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Correction to Bremser and Gallup Jr. (2012)

Wed, 10 Apr 2013 22:30:24 +0000

By Bremser, J. A., Gallup Jr., G. G.

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Born both ways: The alloparenting hypothesis for sexual fluidity in women

Sun, 07 Apr 2013 18:19:38 +0000

By Kuhle, B. X., Radtke, S.

Given the primacy of reproduction, same-sex sexual behavior poses an evolutionary puzzle. Why would selection fashion motivational mechanisms to engage in sexual behaviors with members of the same sex? We propose the alloparenting hypothesis, which posits that sexual fluidity in women is a contingent adaptation that increased ancestral women’s ability to form pair bonds with female alloparents who helped them rear children to reproductive age. Ancestral women recurrently faced the adaptive problems of securing resources and care for their offspring, but were frequently confronted with either a dearth of paternal resources due to their mates’ death, an absence of paternal investment due to rape, or a divestment of paternal resources due to their mates’ extra-pair mating efforts. A fluid sexuality would have helped ancestral women secure resources and care for their offspring by promoting the acquisition of allomothering investment from unrelated women. Under this view, most heterosexual women are born with the capacity to form romantic bonds with both sexes. Sexual fluidity is a conditional reproductive strategy with pursuit of men as the default strategy and same-sex sexual responsiveness triggered when inadequate paternal investment occurs or when women with alloparenting capabilities are encountered. Discussion focuses on (a) evidence for alloparenting and sexual fluidity in humans and other primates; (b) alternative explanations for sexual fluidity in women; and(c) fourteen circumstances predicted to promote same-sex sexual behavior in women.

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Strategic reactions to infants: Female self-presentation in a romantic context

Sun, 07 Apr 2013 17:29:16 +0000

By Dosmukhambetova, D., Manstead, A. S. R.

Research has demonstrated that humans engage in various self-presentational behaviours in the context of mate attraction. We build and expand on these efforts by showing that female facial behaviour also responds to the manipulation of romantic motivation in ways congruent with the logic of evolutionary theory. Given that childbearing is an important goal of human courtship, we hypothesized that during the initial stages of romantic encounters one way that women can advertize their quality is through their emotional reactions to children. Two studies were conducted to determine whether women would self-present in the context of romance by augmenting positive reactions (e.g., smiling more) or by attenuating negative reactions (e.g., frowning less). In both studies participants were undergraduate psychology students. Study 1 was an online study; it examined reported facial expressions towards and cognitive evaluations of infants. Study 2 was a laboratory study in which participants’ spontaneous facial behavior was videotaped while they watched a video of infants (vs. a neutral film). In both studies we found support only for the hypothesis that, when in a romantic context, women attenuate negative reactions. Such attenuation was found for facial expressions, but not for cognitive or affective evaluations of infants.

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Guns, germs, and stealing: Exploring the link between infectious disease and crime

Wed, 27 Mar 2013 18:34:21 +0000

By Shrira, I., Wisman, A., Webster, G.

Can variation in crime rates be traced to the threat of infectious disease? Pathogens pose an ongoing challenge to survival, leading humans to adapt defenses to manage this threat. In addition to the biological immune system, humans have psychological and behavioral responses designed to protect against disease. Under persistent disease threat, xenophobia increases and people constrict social interactions to known in-group members. Though these responses reduce disease transmission, they can generate favorable crime conditions in two ways. First, xenophobia reduces inhibitions against harming and exploiting out-group members. Second, segregation into in-group factions erodes people’s concern for the welfare of their community and weakens the collective ability to prevent crime. The present study examined the effects of infection incidence on crime rates across the United States. Infection rates predicted violent and property crime more strongly than other crime covariates. Infections also predicted homicides against strangers but not family or acquaintances, supporting the hypothesis that in-group–out-group discrimination was responsible for the infections–crime link. Overall, the results add to evidence that disease threat shapes interpersonal behavior and structural characteristics of groups.

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Throwing out the mismatch baby with the paleo-bathwater: A review of Marlene Zuk, Paleofantasy: What Evolution Really Tells Us about Sex, Diet, and How We Live

Tue, 26 Mar 2013 19:58:36 +0000

By Deaner, R. O., Winegard, B. M.

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Female attraction to appetitive-aggressive men is modulated by women’s menstrual cycle and men’s vulnerability to traumatic stress

Wed, 20 Mar 2013 20:48:12 +0000

By Giebel, G., Weierstall, R., Schauer, M., Elbert, T.

Many studies have reported that during high fertility points in the menstrual cycle, women demonstrate increased preference for men with masculinized faces and bodies. In this study, we analyzed whether appetitive aggression in men serves as an additional signal for a favored partner choice. Appetitive aggression describes the intrinsic motivation to act violently even when not being threatened. This study evaluated the responses of 1212 women to one of four descriptions regarding a soldier´s experience after returning from war. The four vignettes included trauma related symptoms with high or low appetitive aggression, or no trauma related symptoms with high or low appetitive aggression. Participants rated their desirability for the soldier in regards to potential long-term and short-term relationships. Results indicate that women preferred a soldier high in appetitive aggression as a short-term mate but not as a long-term relationship. This preference for the “warrior” was higher for women in their fertile window of the menstrual cycle. We conclude that women in their fertile window prefer men exhibiting higher appetitive aggression as a short-term partner, revealing appetitive aggression in men may serve as a signal for a higher genetic fitness.

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Sexual whodunits and evolutionary psychology: The shaping of three novels

Mon, 18 Mar 2013 16:35:36 +0000

By Baker, R.

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