Modulation of the attentional response to baby schema by testosterone in pedohebephilic men and its relation to the nurturing system

Previous fMRI research found increased brain responses in men with pedophilic interest to non-sexual pictures of child and animal faces. This raised the question of whether an aberrant nurturing system could be linked to pedophilia. To further explore this hypothesis, 20 pedohebephilic and 23 teleiophilic men performed a target detection task with adult versus infant human and animal faces, which measured selective attention towards the baby schema by comparing reaction times to infant versus adult targets that were presented amongst distractors of the other category. Since the response to baby schema can be influenced by steroid hormones, saliva samples were additionally collected to determine endogenous testosterone, progesterone, estradiol and cortisol. Contrary to expectations, all men did not react faster to infant than adult faces. Yet, pedohebephilic men were more distracted by infant's faces than teleiophilic men. Pedohebephilic men with higher testosterone were faster in orienting attention to infant targets in the context of adult distractors. This association was not observed in teleiophilic men. Our results support the idea of an overactive nurturing system in pedophilia, which may be influenced by the endogenous testosterone level.

The role of exogenous testosterone and social environment on the expression of sociosexuality and status-seeking behaviors in young Chilean men

Testosterone plays an important role as a social hormone. Current evidence suggests that testosterone is positively related to sociosexuality increasing the psychological attitudes toward investing in short-term versus long-term mating and promotes status-seeking behaviors both by dominance and prestige. In addition, the social environment may play an important role in the expression of mating effort through changes in sociosexuality and status-seeking behaviors. However, the causal relationships among the mentioned variables are still debated. We employed a double-blind, placebo-controlled within-individual design, in order to test and integrate the proposed causal relationships between testosterone and social environment over short-term and long-term mating orientation and dominant and prestigious status-seeking behaviors in a sample of 95 young Chilean men. We did not find evidence that the administration of exogenous testosterone increased short-term or decreased long-term mating orientation as expected. Moreover, exogenous testosterone did not affect either aggressive or cooperative behavior failing to support the social status hypothesis. We also did not find any relationship between short or long-term mating orientation with status-seeking behaviors. Finally, we found support for the effect of social environment on sociosexual attitudes but not over status-seeking behaviors. Thus, men reported higher levels of short-term mating orientation in the presence of a woman compared to a man and no differences were found for long-term mating orientation. We argue that sociosexuality may be expressed flexibly, but contextual factors such as the presence of women seem more important than changes in testosterone levels.

Not all "caregivers" are created equal: Liking, caring and facial expression responses to the baby schema as a function of parenthood and testosterone

The baby schema elicits care from potential caregivers. However, much of the research on the baby schema is based on self-report only. To address this issue, we explored the effects of baby schema and child age on facial expressions (EMG) and eye-blink startle, in addition to self-reported liking and caring for 43 men and 48 women (39 parents). Further, basal testosterone was assessed. All groups responded with liking and caring to high baby schema, but only women also responded with more positive facial expressions. Caring and smiling towards infants compared to first graders depended on parenthood and testosterone levels. Basal testosterone levels were negatively associated with overall responsiveness to children in women and fathers, but positively in non-fathers. Whereas the baby schema overall lead to positive affect and caring, the scope of these responses and the processes underlying them depended on gender, parenthood and hormonal status.

Women's fertility cues affect cooperative behavior: Evidence for the role of the human putative chemosignal estratetraenol

Previous studies demonstrating that women's body odor during ovulation is perceived as more attractive suggest that exposure to women's chemosignals of high fertility increases mating motivation. Building on previous evidence showing that cooperative behaviors are perceived as attractive, in the current study we investigated whether chemosignals of women's fertility affect men's tendency to behave cooperatively. In the first experiment we found that in the presence of women's body odor during ovulation, men increase their tendency to apply a cooperative strategy, while their tendency to apply an individualistic strategy decreases. To examine the mechanism underlying this effect, we tested a different sample of men exposed to the putative human pheromone estratetraenol (estra-1,3,5(10),16-tetraen-3-ol) or to a control solution. Exposure toestratetraenol compared with control yielded strikingly similar effects of increased cooperation. The results indicate that women's chemosignals of high fertility increase mating motivation among man, encouraging them to act in a cooperative manner toward others, a response that may highlight their attractive qualities and thus attract mates. We further conclude that estratetraenol may serve as one of the biological agents that mediate the behavioral effects of women's chemosignals of fertility on social behavior.

An assessment of the mating motive explanation of the beauty premium in market-based settings

Labor market and real-life studies were not designed to discriminate between evolutionary and taste-based and stereotype explanations for the beauty premium, have too many confounding effects, and lack crucial information. Smaller-stake and experimental studies provide more compelling evidence in favor of mating motives and suggest the direction of future research for the economists' field studies.

The type of behavior and the role of relationship length in mate choice for prosociality among physically attractive individuals

Two further key aspects of prosociality as a sexual signal are explored here. First, the context in which it is used (in particular, relationship length) and, second, the different types of prosocial behaviors that exist in social interactions. Therefore, this commentary can show why prosocial behaviors are biased toward physically attractive individuals, as they can gain valuable information from them.

Explaining financial and prosocial biases in favor of attractive people: Interdisciplinary perspectives from economics, social psychology, and evolutionary psychology

Financial and prosocial biases in favor of attractive adults have been documented in the labor market, in social transactions in everyday life, and in studies involving experimental economic games. According to the taste-based discrimination model developed by economists, attractiveness-related financial and prosocial biases are the result of preferences or prejudices similar to those displayed toward members of a particular sex, racial, ethnic, or religious group. Other explanations proposed by economists and social psychologists maintain that attractiveness is a marker of personality, intelligence, trustworthiness, professional competence, or productivity. Evolutionary psychologists have argued that attractive adults are favored because they are preferred sexual partners. Evidence that stereotypes about attractive people are causally related to financial or prosocial biases toward them is weak or nonexistent. Consistent with evolutionary explanations, biases in favor of attractive women appear to be more consistent or stronger than those in favor of attractive men, and biases are more consistently reported in interactions between opposite-sex than same-sex individuals. Evolutionary explanations also account for increased prosocial behavior in situations in which attractive individuals are simply bystanders. Finally, evolutionary explanations are consistent with the psychological, physiological, and behavioral changes that occur when individuals are exposed to potential mates, which facilitate the expression of courtship behavior and increase the probability of occurrence of mating. Therefore, multiple lines of evidence suggest that mating motives play a more important role in driving financial and prosocial biases toward attractive adults than previously recognized.

HUMAN ALTRUISM AND COOPERATION EXPLAINABLE AS ADAPTATIONS TO PAST ENVIRONMENTS NO LONGER FULLY EVIDENT IN THE MODERN WORLD

Evolutionary theory predicts rigorous competition in nature and selfish behavior is thus seen as its inevitable consequence. Evidence of altruistic and cooperative behavior therefore appears at odds with evolutionary theory. However, evolutionary psychology suggests that past environments may be different from the current environments that humans inhabit. Here it is hypothesized that competition in two past environments might have led to strategies that favored altruism and cooperation toward nonkin. First, the expansion of the human brain is seen as requiring long-term, quality parental investment to sustain it. Altruistic displays could well have signaled an ability and willingness to provide such parental investment in a potential mate and been favored as a result. Second, the development of extra-somatic weapons is seen as leading to competition within hominin groups becoming more costly as disputes would have become lethal. A cooperative strategy could have achieved greater net fitness if the benefits of reduced involvement in such lethal disputes exceeded the costs of cooperation. Genes associated with human altruism and cooperation toward nonkin could thus have increased infrequency and come to be expressed in modern human populations despite the environments in which they evolved no longer being fully evident in the modern world.