Hormonal changes after competition predict sex‐differentiated decision‐making

Recent neuroendocrinology research has pointed out that testosterone (T) and cortisol (C) changes after social interactions can predict risk‐taking behavior in decision‐making, depending on the sex of participants. However, previous research has focused on the effects of the changes in only one hormone, rather than the interaction between them, even though C can suppress T activity. Our aim was to test, in men and women, the role of T changes moderated by C changes after competition in decision‐making. Thus, 48 males and 46 females completed the Iowa Gambling Task (IGT) after a laboratory competition or a noncompetitive task (control task). Saliva samples were collected before and after the competition/control task. IGT was employed to measure risk‐taking decision‐making, considering the degree of uncertainty. Our results showed sex‐differentiated effects of T and C changes on risk‐taking behavior. On the one hand, men from both task groups (Competition/Control) who had higher C and T changes after competition showed more risk‐taking decision‐making (higher IG Risk). On the other hand, women from the competitive task who had high C and T showed conservative decision‐making. Therefore, these results show sex‐differentiated decision‐making profiles, which would help to understand how men and women behave after experiencing a competitive social context.     

Upper‐Body Strength and Political Egalitarianism: Twelve Conceptual Replications

Animal models of conflict behavior predict that an organism's behavior in a conflict situation is influenced by physical characteristics related to abilities to impose costs on adversaries. Stronger and larger organisms should be more motivated to seek larger shares of resources and higher places in hierarchies. Previous studies of human males have suggested that measures of upper‐body strength are associated with measures of support for inequality including Social Dominance Orientation (SDO), a measure of individual differences in support for group‐based hierarchies. However, other studies have failed to replicate this association. In this article, we reexamine the link between upper‐body strength and support for inequality using 12 different samples from multiple countries in which relevant measures were available. These samples include student and locally representative samples with direct measures of physical strength and nationally representative samples with self‐reported measures related to muscularity. While the predicted correlation does not replicate for every single available measure of support for inequality, the overall data pattern strongly suggests that for males, but not females, upper‐body strength correlates positively with support for inequality.     

正常人以及精神障碍人群在合作与竞争中的表现

合作与竞争是社会互动的两种主要形式,也是冲突解决的两种方法,对人际交往具有重要作用,一直以来都受到研究者的广泛关注。但是从心理与社会学角度研究合作与竞争的文献却相对较少,而对于精神障碍人群在合作与竞争中异常表现的原因目前也存在争议。本文从心理与社会学的角度出发,对合作与竞争的神经机制和生物基础进行综合论述,并对精神障碍人群在合作与竞争两种社会互动中的表现进行比较,试图为精神障碍人群在人际交往中的康复训练提供理论依据。     

Aggression and testosterone: Testing a bio-social model

Based upon reports of a positive correlation between circulating testosterone levels and aggression, we draw upon evolutionary psychology to place the action of testosterone in a broader perspective. We propose that testosterone affects competitive status-seeking and that under certain circumstances (including youth) this is expressed as aggression. Involvement in aggression in turn is associated with adherence to an instrumental social representation of aggression which justifies aggression as a means of imposing control over others and increasing self-esteem. Measures of salivary testosterone, masculinity, preferred social representation of aggression, and multiple aggression scales were collected from an undergraduate sample of 119 men. An Aggression factor was derived from principle components analysis of the aggression measures. The strongest correlates of Aggression were holding an instrumental social representation of aggression and youth. Testosterone showed no significant relationship to the single or aggregate measures of aggression or to any of the other psychometric measures. We suggest ways in which previous work may have over-estimated the strength of the association between circulating testosterone and aggression and discuss the possible relationships between age, social representation, and aggression. Aggr. Behav. 23:239–238, 1997. © 1997 Wiley-Liss, Inc.     

Lex talionis: Testosterone and the law of retaliation

Research examining both the organizing and activating effects of testosterone in one-shot bargaining contexts has been vexed by inconsistencies. Some research finds that high-testosterone men are more likely to reject unfair offers in an ultimatum game and exogenous administration of testosterone to men leads to less generous offers. In contrast, other research finds that higher prenatal exposure to testosterone predicts more generous dictator game offers and administering testosterone to women leads to more generous ultimatum game offers. The current research seeks to resolve these inconsistencies by examining how the organizing effects of testosterone affect bargaining behavior. Because testosterone is associated with status seeking and concerns with social reputation, we hypothesized that testosterone would predict aggressive bargaining but only after provocation. Two studies found that prenatal testosterone exposure, as measured by 2D:4D ratio, led to aggressive responses for both males and females, but only after they received unfair offers. Furthermore, perceptions of fairness violations moderated but did not mediate the effect of testosterone on retributional responding. These results suggest that the organizing effects of testosterone have consistent effects on bargaining behavior for both males and females but its predictive ability requires some form of provocation to emerge.     

Prenatal testosterone and preschool Disruptive Behavior Disorders

Disruptive Behavior Disorders (DBD), including Oppositional-Defiant Disorder (ODD) and Attention-Deficit/Hyperactivity Disorder (ADHD), are fairly common and highly impairing childhood behavior disorders that can be diagnosed as early as preschool. Prenatal exposure to testosterone may be particularly relevant to these early-emerging DBDs that exhibit a sex-biased prevalence rate favoring males. The current study examined associations between preschool DBD symptom domains and prenatal exposure to testosterone measured indirectly via right 2D:4D finger-length ratios. The study sample consisted of 109 preschool-age children between ages 3 and 6 (64% males; 72% with DBD) and their primary caregivers. Primary caregivers completed a semi-structured interview (i.e., Kiddie Disruptive Behavior Disorder Schedule), as well as symptom questionnaires (i.e., Disruptive Behavior Rating Scale, Peer Conflict Scale); teachers and/or daycare providers completed symptom questionnaires and children provided measures of prenatal testosterone exposure, measured indirectly via finger-length ratios (i.e., right 2D:4D). Study results indicated a significant association of high prenatal testosterone (i.e., smaller right 2D:4D) with high hyperactive–impulsive ADHD symptoms in girls but not boys, suggesting that the effect may be driven by, or might only exist in, girls. The present study suggests that prenatal exposure to testosterone may increase risk for early ADHD, particularly hyperactivity–impulsivity, in preschool girls.     

Agonistic rank,aggression, social context,and testosterone in male pigtail monkeys

Two groups of pigtail monkeys were merged, a third was formed, and individual males were introduced into a group in a series of experiments examining the effects of social context upon agonistic rank, aggressive expression, and testosterone levels. In the first experiment, two heterosexual groups, containing adult males unfamiliar to the other group, were merged. The two groups fought, and the smaller group was defeated. The alpha and beta males of the defeated group were singled out for repeated attack and both showed significant drops in circulating levels of testosterone. Both males were removed from the group during the first day, but testosterone levels did not recover to baseline levels for several days. The alpha male of the victorious group, on the other hand, showed a significant rise in testosterone, which was apparent only on the day following the merger. In order to study the influence of previous social familiarity on male reception into a group, another group was formed by removing males from the victorious group and placing them in a separate enclosure. The males in the new group established a dominance hierarchy unrelated to their previous social ranks with one another. Three months later, each of the six adult males remaining in the parent group was individually introduced into the new group for one day or less. Each of the males introduced into the new group accepted a social position at the lower end of the dominance hierarchy without regard to his previous rank relationships with the host males when they were all in the parent group. Even the alpha and beta males of the parent group were relegated to low rank positions in the new group, despite having ranked over each of the host males since birth. In contrast to the aggression directed at the unfamiliar males in the first experiment, a minimum of aggression was directed to the familiar males introduced into the new group in the second experiment. Although the males introduced accepted low social ranks, it appeared that each was readily integrated into the group with a minimum of aggressive interaction during the time he was scheduled to remain in the group. There were no significant changes in circulating levels of testosterone in any of the males during the introductions of familiar males to one another.     

Urinary testosterone metabolite levels and aggressive behaviors in male and female bonobos (Pan paniscus)

This study presents the first data on the relationship between testosterone (T) and aggression in both sexes of the bonobo (Pan paniscus). Morning urinary concentrations of T metabolites (measured by immunoreactive 5α–androstane–17α–ol–3–one) were used to reflect T status. Results show that first, no correlation of T metabolite levels with any of the aggressive behaviors was found between individuals. Within an individual, T metabolite levels only correlated with a minority of aggressive behaviors. Hence, social factors are likely of major importance for the occurrence of aggression in this highly gregarious species, but certain intraindividual aspects of aggressive behavior are nevertheless related to T. A more detailed discussion of the results follows. Secondly, all correlations with T were similar for every individual, males and females, suggesting an analogous relationship in both sexes. Thirdly, our study confirms for bonobos that the measure of aggression used, the time scale at which the correlation is studied, and whether this is done on an inter‐ or intraindividual level, considerably affect results. Aggr. Behav. 30:425–434, 2004. © 2004 Wiley‐Liss, Inc.     

Relationship of testosterone to men's family functioning at mid-life: A research note

Sociobiological theory suggests that aggression coupled with altruism is highly adaptive for males in all social systems, including the family, whereas sex-role convergence theory indicates that lower levels of aggression are most adaptive for men, particularly at mid-life. The purpose of this study was to determine the role that testosterone, as a proxy for aggression, plays as an adaptive mechanism in the lives of middle-aged males. The sample used in this study consisted of 37 middle-aged (39–50 years of age) males employed in professional occupations in a midwestern metropolitan area. Testosterone levels were regressed on factors typically found to be related to male satisfaction with family life at mid-life: marital satisfaction, parent-adolescent communication, amount of emotional expressiveness, and androgynous characteristics; recent positive and negative stressors and trait anxiety were statistically controlled. Results of step-wise multiple regression analysis indicated that low levels of testosterone were significantly (R = .34, P < .01) related to enhanced marital and parental relationships and androgynous behaviors; however, emotional expressiveness was significantly related to high levels of testosterone.     

Differential sexual activity of isolated and grouped male mice despite testosterone administration

In Experiment 1, adult male C57 mice were castrated, housed individually or in groups of four, and repeatedly injected with either of two doses of testosterone. Control mice were sham-castrated, individually or group housed, and injected with oil vehicle. In repeated tests of sexual behavior with receptive females, isolated males in all surgery-dose combinations showed significantly more mounts and intromissions than did their group-housed counterparts. Ejaculations were fully restored by testosterone in castrated grouped males but not in castrated isolated males. In Experiment 2, administration of either of two doses of testosterone failed to elevate the sexual behavior of intact group-housed males. These experiments show that housing with other males depresses all major measures of sexual behavior, and suggest that this is probably independent of testicular hormones.     

The structure of prejudice: associative strength as a determinant of stereotype endorsement

Previous research obtained inconsistent findings as to whether implicit and explicit measures of prejudice are related. According to our view, some of these inconsistencies are due to whether implicit measures assess exclusively the strength of association between the social category and the evaluation or the activation of the social category in addition. Derived from recent theorizing we suggest that it is especially associative strength between the social category and its evaluation that determines the endorsement of prejudice assessed in explicit measures. To test this assumption we used the Implicit Association Test (IAT) to assess the associative strength of German students' prejudice towards Turkish people and the Blatant‐and‐Subtle‐Prejudice‐Scale (BS scale) as an explicit measure of prejudice. We obtained evidence for prejudice at a relative level in that the category of Turks was more closely associated with a negative evaluation and the category of Germans more closely associated with a positive evaluation. In line with our assumptions the implicit measure was correlated with the explicit measure in that the stronger the representation of Turks was associated with a negative evaluation the more prejudiced individuals responded in the explicit prejudice measure. Using a trait assignment technique, we found that neither associative strength nor the endorsement of the prejudice in the explicit measure were related to the contents of the stereotype. Copyright © 2001 John Wiley & Sons, Ltd.     

Relationships between digit ratio 2D:4D and self-reported aggression and risk taking in an online study

2D:4D, the length ratio of the second to the fourth digit, is a putative measure of prenatal testosterone, which may have effects on aggression and risk taking. Participants in a German online study (>1000 females, >1200 males) submitted their self-measured digit lengths and self-report measures on verbal and physical aggression and risk taking. For males, left-hand 2D:4D and verbal aggression correlated significantly (r = −.10, after correction for age and reduced reliability in self-measured 2D:4D), with other relationships being similar but non-significant. For females, no relationships between aggression and 2D:4D were found. Risk taking and right-hand 2D:4D correlated significantly in women (r = −.10, after correction for age and reduced reliability in self-measured 2D:4D); similar, but statistically non-significant, relationships were found in men. The result corroborates an emerging view that 2D:4D is negatively related to aggression in males and that 2D:4D is negatively related to risk taking. This tentatively points to effects of prenatal testosterone on these characteristics.     

Submitting to defeat: social anxiety, dominance threat, and decrements in testosterone

ABSTRACT— Although theory suggests a link between social anxiety and social dominance, direct empirical evidence for this link is limited. The present experiment tested the hypothesis that socially anxious individuals, particularly men, would respond to a social-dominance threat by exhibiting decrements in their testosterone levels, an endocrinological change that typically reflects pronounced social submission in humans and other animals. Participants were randomly assigned to either win or lose a rigged face-to-face competition with a confederate. Although no zero-order relationship between social anxiety and level of testosterone was observed, testosterone levels showed a pronounced drop among socially anxious men who lost the competition. No significant changes were observed in nonanxious men or in women. This research provides novel insight into the nature and consequences of social anxiety, and also illustrates the utility of integrating social psychological theory with endocrinological approaches to psychological science.     

Testosterone and attribution of successful competition

Mood, personal merit, and/or its perception have been suggested to be mediating factors in testosterone responses to competition. Previously we have found that personal contribution and attribution were related to testosterone levels after successful competition. To confirm such associations, two basketball teams (n = 17 players) that emerged as winners in two actual matches were studied. Salivary testosterone levels and mood were measured before and after the games. Individual contribution to the outcome was assessed, and personal satisfaction and causal attribution of outcome were reported by players. Testosterone concentrations increased to near significance in Team 1 but not in Team 2, who attributed their victory more to luck than did Team 1. This latter team showed notably decreased vigor, and both teams showed fatigue at the end of the match. Post‐match testosterone levels were only significantly, negatively related to external attribution. The results support the idea that causal attribution of the outcome is contributing to the variance of the testosterone responses to real confrontations where the outcome is highly dependent on personal merit. Aggr. Behav. 26:235–240, 2000. © 2000 Wiley‐Liss, Inc.     

Testosterone as a social inhibitor: two case studies of the effect of testosterone treatment on language

This study aimed to correlate testosterone levels with natural written language in 2 people undergoing testosterone therapy. Two participants, a man receiving treatment for loss of upper-body strength and a female-to-male transgendered individual, supplied records of injections over 1-2 years along with e-mails or journal entries as writing samples. Results showed that higher testosterone levels correlated with reduced use of words related to social connections. Language relating to anger, sexuality, and achievement was unrelated to testosterone levels. It appears that testosterone steers attention away from social connections but not necessarily toward concerns with aggression or sexual activity.     

Role of neonatal androgens in sexual differentiation of brain structure, scent marking, and gonadotropin secretion in gerbils

Gerbils display a sexually dimorphic scent marking behavior that responds to testosterone (T) in adulthood and develops under the influence of testosterone perinatally. A complex of cell groups between the preoptic area and anterior hypothalamus of the gerbil brain is also sexually dimorphic and responsive to testosterone. One of these cell groups, the sexually dimorphic area pars compacta (SDApc), usually exists only in males. Even when given testosterone, adult female gerbils rarely have an SDApc. To determine if the SDApc develops under the influence of testosterone, male gerbils were castrated or given sham operations on the day they were born or 1 day later, or were not manipulated. Female gerbils were injected subcutaneously with 0, 50, or 100 micrograms testosterone propionate (TP) on the day after birth. When given ovarian transplants as adults, neonatally castrated males scent marked at low levels typical of females. Neonatally androgenized females given testosterone as adults scent marked at high levels typical of males. Neonatal castration did not affect the probability that the SDApc would develop, but neonatal androgenization did. Half the females given either dose of TP as neonates had SDApcs bilaterally. The sizes of the SDApcs present in females depended on the dose of testosterone given neonatally. The larger dose produced larger SDApcs. The 100-micrograms dose of TP also defeminized gonadotropin secretion, but the 50-micrograms dose did not. The castration of males neonatally prevented the defeminization normally caused by endogenous testosterone. Both groups of neonatally castrated males formed corpora lutea in their ovarian transplants, but control males did not.     

Constructing culture in cowbirds (Molothrus ater)

In past work, the authors produced divergent patterns of courtship and communication in juvenile male cowbirds (Molothrus ater) by providing them with different social experiences during their 1st year. Here the authors determined whether these different social patterns could be transmitted to new generations of juvenile males. In Experiment 1, the authors exposed groups of juveniles to adult males who differed in the amount of male-male competition they produced. In Experiment 2, they gave groups of juveniles either social access to adult males or only visual and acoustic access to those males. In both experiments, juvenile males developed patterns of courtship and competition similar to those expressed by the adult males with whom they had social contact. The juveniles never had the opportunity to observe some of the adults' behaviors that they came to replicate. This suggests that the role of the adults was to establish the social structure in the groups, modifying juveniles' early social interactions. Juveniles were then "cultured" within these different learning environments, constructing social behavior similar to the adult males' behavior in their 1st year.     

Ares and Babbitt in the classroom: effects of competition and reward on children's aggression.

In many competitive situations, aggression is one of several instrumental behaviors that can produce reinforcing consequences. Despite the fact that aggression precipitated by competition for valued resources is an increasingly important social problem, there is little evidence of a causal relationship. In a factorial experiment, dyads of 64 kindergarten and first-grade males played a game in a face-to-face setting that yielded a prize for the winner only. It was predicted that high levels of competition and high levels of reward magnitude would produce more aggressive behavior than lower levels of these variables. Additionally, children rated by their teachers as high in dispositional aggressiveness were anticipated to behave most aggressively in the game. Each of these predictions was confirmed on three different measures of aggression: verbal, interference, and physical. Furthermore, the data suggested that constructive action was sometimes abandoned in attempts to harm an opponent. Since competition for desirable objects is a social reality, it was concluded that conditions inhibiting aggression in these situations should be investigated.     

Androgens and aggressive behavior in primates: A review

This review deals with possible central and peripheral effects of androgens upon primate aggressive behavior. One problem that clouds interpretation of experimental work is that measurements of dominance have often been employed, such as competition tests for food and water. Such measures often do not correlate with those obtained by quantifying aggressive interactions. It should be remembered that very few of the 188 primate species have been studied experimentally and that great behavioral and physiological diversity occurs within the order. Therefore, generalizations about the effects of androgens upon aggressive behavior in primates (including man) should be made with caution. Testosterone has an organizing influence upon the foetal brain of rhesus monkeys and may affect the development of neural mechanisms which govern aggression in males. More data are required on primates, however, since rhesus monkeys show some important differences from rodents as regards the effects of androgen upon sexual differentiation of the hypothalamus. In future, marmosets may provide a suitable model for such studies, because there is evidence that sexual differentiation of brain by androgen occurs postnatally in these monkeys. At puberty, male primates show a variety of behavioral changes and, during adulthood, males of seasonally breeding species may be more aggressive during the mating season, when testosterone levels are maximal. This does not indicate a causative relationship between testosterone and aggressive responses, because castration and androgen treatments have little effect upon aggression in prepubertal or adult males of several primate species. Androgens have pronounced effects on sexual responses in adult male monkeys, but their central effects upon aggression are much less important than among rodents. Elec trical stimulation of hypothalamic pathways has been employed to evoke aggressive behavior in marmosets and rhesus monkeys. In the rhesus, preliminary evidence indicates that such pathways show some sensitivity to androgens. In rodents it is known that these areas are richly supplied with monoaminergic neurons, which play an important role in aggressive behavior. There is little evidence on primates, however, and this remains a crucial topic for future research. Peripheral effects of androgens should also be considered. Many prosimians and New World monkeys use scent-marking behaviors and, in males, androgen-dependent chemical cues may be involved in sexual recognition and territorial behavior. This possibility awaits investigation. Finally, plasma testosterone levels may alter as a function of aggression itself; thus levels decrease if male rhesus monkeys are defeated by conspecifics. This might occur because neural events associated with giving (or receiving) aggression also influence pituitary function and hence alter gonadal testosterone secretion. Theoretically, it is possible that such changes in circulating testosterone might affect aggressive behavior via a feedback action on the brain, but the experimental evidence does not support such a view.     

Three aspects of self-disclosure as they relate to quality of adjustment

Subjects completed two measures of actual self-disclosure (one for intimacy of self-presentation and one for inwardness of self-presentation)and a self-report of past self-disclosure. and California Psychological Inventory. For both sexes the two measures of actual disclosure correlated positively but neither instrument related positively to the self-report measure. Females disclosed more than males on both measures of actual disclosure. Quadratic, inverted-U relationships were hypothesized for the self-disclosure and CPI scales, but by and large they were not found. Linear associations were noted, the major ones being a positive pattern of correlations between the inwardness of actual disclosure and measures of flexible autonomy, responsibility and socialization for the males, a negative set of relations between the intimacy of actual disclosure and scales indicative of good interpersonal adjustment for the females, and a positive relationship between the self-report measure and scales indicative of social poise, extraversion and socialization for both sexes.