Some subordinates are more equal than others: Play fihgting amongst adult subordinate male rats

Adult male rats living together form dominance relationships, with one dominant and the remainder adopting subordinate roles. In previous studies, it was shown that in adult male pairs, the subordinate rat initiates more playful contacts and retains a more juvenile response to the playful contacts by the dominant. In this experiment, triads were used to examine the play between subordinate males. The subordinates directed fewer playful contacts to each other than to the dominant rat, and there was a symmetrical play relationship between the subordinates. After the dominant was removed from the colony, one subordinate became the dominant. Playful interactions amongst these pairs increased, with the subordiante intiating more playful contacts than the dominant. Furthermore, from a similarly low frequency of juvenile-type response to playful contact to each other when in triads, the subordinate in the dyads increased its frequency of juvenile responses to the dominant partner. This supports the hypothesis that the playful behavior of subordinate male rats towards the dominant is an adaptive response, playful behavior of subordinate male rats towards the dominant is an adaptive response, serving a “friendship maintenance” function. Finally, when in triads, one subordinate was more playful with the dominant than the other subordinate. It was the least playful subordinate that was the most likely to become the dominant. This sugests that within a colony, not all subordinates are the same. © 1993 Wiley-Liss, Inc.     

Fighting experiences and natural killer cell activity in male laboratory mice

There is currently much interest in the potential impact of psychological factors on immune responses. An attempt was made to assess the effects of dominant/subordinate polarity in male mice on the cytotoxic activities of their natural-killer (NK) cells. On the basis of repeated agonistic encounters, categories of subordinate and dominat animals were selected. These animals were compared with manipulated controls (introduced to a novel test cage without an opponent on each occasion) and undisturbed controls (who remained in isolation without manipulation). In terms of NK activity, immunosuppression was observed in both dominant and subordinate categories when compared to undisturbed controls. There were, however, no differences between the fighting exposed subjects and the manipulated controls, suggesting that stress accounts for any changes. © 1994 Wiley-Liss, Inc.     

Effects of prior agonistic experience on risk assessment and approach behavior evoked by familiar or unfamiliar conspecific odors

Risk assessment and appetitive behaviors in response to familiar and unfamiliar conspecific odors were measured in mice rendered dominant or subordinate by a series of resident-intruder encounters. Subordinate mice showed elevated levels of risk assessment in response to the odors of both familiar dominant and unfamiliar males. These behaviors were almost totally absent among dominant males exposed to familiar subordinate or unfamiliar male odors. Subordinate mice showed a marginally significant elevation in latencies to approach familiar, but not unfamiliar, dominant odors. Dominant and subordinate mice spent comparable amounts of time in the cage area containing familiar antagonist odors, however, and the durations of subordinates were mildly elevated, rather than decreased, when unfamiliar conspecific odors were present. There were no group differences in any of the appetitive behaviors. These findings suggest that apparent preferences for conspecific odors may arise from quantitatively and/or qualitatively differing emotional states. The inclusion of risk assessment measures is suggested to be a useful adjunct for studies of olfactory preference/rejection. © 1994 Wiley-Liss, Inc.     

When is the Wilcoxon–Mann–Whitney procedure a test of location? Implications for effect-size measures

The Wilcoxon–Mann–Whitney procedure is invariant under monotone transformations but its use as a test of location or shift is said not to be so. It tests location only under the shift model, the assumption of parallel cumulative distribution functions (cdfs). We show that infinitely many monotone transformations of the measured variable produce parallel cdfs, so long as the original cdfs intersect nowhere or everywhere. Thus there are infinitely many effect sizes measured as shifts of medians, invalidating the notion that there is one true shift parameter and thereby rendering any single estimate dubious. Measuring effect size using the probability of superiority alleviates this difficulty.     

Examining the item response process to personality measures in high-stakes situations: Issues of measurement validity and predictive validity

We conducted two experimental studies with between-subjects and within-subjects designs to investigate the item response process for personality measures administered in high- versus low-stakes situations. Apart from assessing measurement validity of the item response process, we examined predictive validity; that is, whether or not different response models entail differential selection outcomes. We found that ideal point response models fit slightly better than dominance response models across high- versus low-stakes situations in both studies. Additionally, fitting ideal point models to the data led to fewer items displaying differential item functioning compared to fitting dominance models. We also identified several items that functioned as intermediate items in both the faking and honest conditions when ideal point models were fitted, suggesting that ideal point model is “theoretically” more suitable across these contexts for personality inventories. However, the use of different response models (dominance vs. ideal point) did not have any substantial impact on the validity of personality measures in high-stakes situations, or the effectiveness of selection decisions such as mean performance or percent of fakers selected. These findings are significant in that although prior research supports the importance and use of ideal point models for measuring personality, we find that in the case of personality faking, though ideal point models seem to have slightly better measurement validity, the use of dominance models may be adequate with no loss to predictive validity.     

Intersexual aggression and male sexual activity in captive rhesus macaques

Rape has been posited to be an outgrowth of male reproductive strategies. Forced copulations may have evolved as a consequence of the low parental investment made by males in producing and raising offspring. We designed a laboratory experiment which paired rhesus macaque males with females in order to assess the influence of intersexual aggression on male sexual activity. Younger and older adult males had comparable levels of sexual behavior, but younger males were more aggressive towards females than were older males. In addition, females threatened younger males more than older males. Male attacks on females did not result in sexual intercourse. On the contrary, a negative correlation existed between male aggression towards females and male success at achieving intromissions. Female aggression towards males appeared to be an effective tactic which reduced the chances of sexual intercourse. We conclude that intersexual aggression acts either as a mechanism of dominance assertion or as a means to increase spatial distance between individuals. These data do not support the idea that rape in humans has an evolutionary foundation derived from male reproductive strategies.     

Right-Wing Ideology as a Predictor of Collective Action: A Test Across Four Political Issue Domains

Despite a vast literature documenting motivations for collective action, the role of sociopolitical ideologies, including right-wing ideologies, in predicting collective action is underresearched. Literature on right-wing ideological beliefs suggests that those higher in right-wing authoritarianism (RWA) or social dominance orientation (SDO) hold specific attitudes or endorse specific policies, in part, because of factors such as perceived fear-based threat or empathy. In the present research, structural equation modeling (SEM) was run on pooled data from a diverse Canadian university sample and two American adult samples (total N = 1,469). Participants completed measures of RWA, SDO, fear-based threat, empathy, and domain-specific collective action. Results showed that RWA and SDO both related positively to collective action targeting societal moral breakdown but negatively to collective action aimed at equalizing race relations or fighting climate change. Whereas the indirect effects of right-wing ideologies via fear-based threat or empathy were significant in all four domains for SDO, the indirect effect of RWA was only significant in the climate change domain. Implications are discussed.     

The Ideological Foundations of Economic Protectionism: Authoritarianism,Social Dominance Orientation,and the Moderating Role of Political Involvement

Even though economic globalization and foreign trade are major topics in the political discourse of most societies and negative attitudes toward international trade are prevalent, there is a lack of research investigating the ideological roots of protectionist preferences from a psychological perspective. In the present research, we examined the implications of right-wing authoritarianism (RWA) and social dominance orientation (SDO) for trade attitudes. Using data from two nationally representative samples from the United States (Study 1) and Germany (Study 2), we found that RWA predicted protectionist attitudes above and beyond economic self-interest. Furthermore, we found that the relationship between RWA and opposition to international trade was moderated by political involvement. The association of SDO with protectionist attitudes was inconsistent across the two studies and was not moderated by political involvement. Taken together, these results emphasize the importance of basic ideological orientations and the psychological dispositions they reflect in explaining public attitudes toward international trade.     

Dominance assertion in male chimpanzees (Pan troglodytes)

The social relations of three adult males in a captive chimpanzee group were evaluated for 12 months. The observations encompassed a period of transition in the dominance hierarchy providing an opportunity to assess behavioral patterns involved in the initiation of status changes. This study shows that dominance in the chimpanzee is expressed primarily through ritualized and non-contact behavior rather than by overt aggression. In particular, display behavior is important for indicating dominance rank, in communicating aggressive intent, and as a prelude to status struggles. The functional relationships between status, displays and other socio-sexual behavior patterns are presented.     

Various relationships between predatory dominance and aggressive behavior in Pairs of cats

The experiments were performed on adult male cats selected initially as good mousekillers. Cats were tested in pairs and each pair was introduced separately to the experimental compartment. The attitude toward the partner before and during the predatory competition test as well as superiority in catching and killing the mice, considered as an index of dominance, were registered. In the course of experiment five types of relations between the predatory dominance and aggressive behavior were observed. The concept of dominance as an outcome of several factors was discussed. It was concluded that predatory dominance is not based exclusively on aggressive mechanisms, as it may be formed and sustained without overt aggression.