Sex differences in aggressive behavior in a marsupial,the gray short-tailed opossum (Monodelphis domestica)

In male and female gray short-tailed opossums (Monodelphis domestica), same-sex interactions were characterized by high levels of threat behavior (open-mouth postures and screeching vocalizations). Actual fighting behavior (biting, locking, and tumbling) was seen almost exclusively in male-male interactions. In male-female interactions, females showed high levels of threat behavior and males showed little aggressive behavior of any kind. Clicking vocalizations, submissive behavior in marsupials, were displayed almost exclusively by males. These findings are discussed with respect to the uses of auditory and olfactory communication in marsupials.     

Dominance and aggression in various sized groups of red deer stags

The influence of group size on agonistic behaviour of “white” red deer stags (Cervus elophus L.) of different ranks in the hierarchy was examined during artificial feeding. Size of the social group was dependent on the season in the year and on age and general rank within the whole bachelor group inhabiting the enclosure of the stags. Group size differentially affected the behaviour of the stags according to the rank of the individual in the particular groups. Increased group size resulted in increased agonistic activity in top-ranking stags. The number of attacks directed towards bottom-ranking stags by other group members was also elevated. Stags of intermediate rank position showed a decrease in the number of interactions involved and a suppression of agonistic activity.     

Why do we share aggressive online content? Testing a short cycle model

The present study aimed to observe the impacts of aggressive online content exposure and personality on aggressive content sharing, considering the mediating role of positive and negative affects. A total of 302 Brazilians, equally divided into two groups, participated in a social network simulation, being exposed to aggressive (experimental group) or neutral (control group) posts and choosing what they would like to share on this site (among aggressive or nonaggressive material). A factorial MANOVA showed a significant difference for positive and negative affects and aggressive content sharing (Wilks' Λ = 0.936; F[3, 298] = 6.812; p = .001; η² = 0.064). Through structural equation modeling, an explanatory model was also tested, in which this behavior was directly predicted by aggressive online content exposure and suffered indirect effects from openness, conscientiousness, and extroversion, mediated by positive affects (goodness-of-fit index = 0.997, comparative fit-index = 0.998, Tucker-Lewis index = 0.996, SRMR = 0.028, root-mean-square error of approximation = 0.035, CI = 0.003−0.054). It is possible to conclude that the objectives are met, highlighting the contribution to understanding aggressive online behavior through the proximal processes described in the general aggression model.     

Sex Differences,Weapon Focus,and Eyewitness Reliability

Abstract

Two aspects of eyewitness identification were tested: sex differences in eyewitness reliability and an explanation of the weapon focus effect that is based on object salience. One hundred ninety-one male and female American college students watched a slide sequence that depicted a male or female target person enacting a simple behavioral progression while holding various objects. Afterward, the subjects attempted to identify the target person in a photospread and to recall physical details about him or her on a questionnaire. The results confirmed a predicted own-sex identification bias effect (p < .001) but did not support the object salience hypothesis. An interaction between subject sex and object indicated that men and women attended to and were distracted by different types of objects (p < .009).     

Perceptions of inferred parental ability through sexually dimorphic facial features

In addition to providing robust cues diagnostic of prospective mates' heritable fitness, various physical features could be similarly utilized in inferring individuals' parental abilities. This study sought to explore how variations in sexually dimorphic facial features inform perceptions of social targets as motivated to provide parental care. American undergraduates (N = 244) viewed a series of 12 total male and female faces manipulated at varying degrees of sex-typicality (i.e., masculinized versus feminized versus unaltered controls) on a within-subjects basis, and rated the perceived motivation of each target to nurture and protect a child using items derived from the Parental Care and Tenderness Scale. Female targets were perceived as more motivated by parental care than male targets, F(1, 240) = 14.86, p < .001, η_p² = 0.058, whereas male targets were perceived as specifically motivated to protect offspring, F(1, 240) = 177.32, p < .001, η_p² = 0.425. Feminized targets were additionally perceived as more motivated by nurturance, though such inferences were apparent for both male and female targets, F(1, 240) = 7.36, p < .001, η_p² = 0.058. Findings represent an understanding of perceivers use of functional heuristics of sexual dimorphism in identifying optimal parents.     

The Influence of Sex,Gender, Self-Discrepancies,and Self-Awareness on Anger and Verbal Aggressiveness Among U.S. College Students

Abstract

Among a sample of 445 U.S. college students, the authors examined the extent to which individual differences (e.g., sex, gender, self-discrepancies, self-awareness) explained anger tendencies and verbal aggressiveness. Regression analyses showed that (a) the tendency to repress anger (anger-in) was explained by masculinity, desire to be masculine, and public self-awareness, R ² = .19, F(11, 433) = 8.44, p < .001; (b) the tendency to express anger (anger-out) was explained by sex, masculinity, and public self-awareness, R ² = .17, F(11, 433) = 7.38, p < .001; and (c) willingness to be verbally aggressive was explained by sex, femininity, and private self-awareness, R ² = .32, F(11, 433) = 16.94, p < .001. In addition, different types of individual difference variables accounted for anger tendencies and verbal aggressiveness across sex and gender categories, suggesting that anger and verbal aggressiveness may be driven by different psychological processes across types of participants.     

Female Prairie Deer Mice Prefer Conspecific Flesh Over Contraspecific Flesh

Hungry adult female deer mice were presented with freshly asphyxiated conspecifics and house mice. The deer mice showed a reliable preference for the conspecific flesh during the first 2 hr of testing, but this preference was attenuated during the following 20 hr of testing. Previous research has shown that male deer mice prefer contraspecific flesh. The preference of female deer mice for conspecific flesh is attributed to their tendency to be more aggressive toward living conspecifics than are male deer mice and their tendency to avoid living contraspecifics more than do male deer mice.     

The effects of gender upon doctor-patient interaction

Abstract

Despite extensive research examining doctor-patient communication, relatively link attention has been directed to the impact of gender differences (Weisman and Teitelbaum, 1985). The present study examines the effect of doctor and patient gender on interaction. The consultations of 102 patients (47 male and 55 female) and 15 doctors (8 male and 7 female) were taped and then analysed using a modification of a method developed by Butler and Cox (1992). Measures were also taken of doctor and patient word count, the proportion of doctor dialogue relative to the patient and frequency of interaction exchange. Female patients initiated significantly more agendas than male patients (p >0.001). Those men who raised emotional agendas were more likely to reintroduce these agendas than female patients (p>0.01). particularly in the presence of female doctors (p0.001). Consultations with female patients revealed higher overall (p>0.01) and patient (P>0.01) word count than those with male patients. A positive effect of “gender congruence” upon word count was observed with female doctors only (p0.001).     

The influence of T-shirt graphics on perceptions and behavioral intentions

Do graphics on clothing drive perceptions? We used a between group design to test if athletic, academic, or suggestive graphics on clothing differentially influence perceptions and behavioral intentions. In study 1, participants (N = 199) rated five female t-shirt models, and in study 2 and 3, participants rated five male t-shirt models (N = 120) or university students (N = 50). Analyses of variance controlling for sex (ANCOVA) showed participants were least likely to want to interact with models/students wearing sexually suggestive graphics: Study 1, F(3,165) = 30.263, p < .001, η_p ²  = .30, power = 1.00; Study 2, F (3,119) = 11.630, p < .000, η_p ² = .234, and Study 3, F(1, 42) = 12.578, p < .000. Participants did not rate models in the academic and athletic graphic shirts differently from models with plain white shirts. Results support the concept that people form different perceptions based upon the clothing a person wears, changing behavioral intentions. Neither sex role ideation (Study 1) or sexism (Study 2) were significant covariates of perceptions and intentions.     

The effects of leader gender on self-presentational concerns in exercise

The present study examined the impact of the exercise leader's gender on the self-presentational concerns of women in a live exercise class. Eighty-seven college-aged non- or infrequent exercisers participated in a group exercise class led by either a female or male instructor. Participants completed measures of Self-Presentational Efficacy (SPE), State Social Anxiety (SSA) and State Social Physique Anxiety (SPA-S) prior to and following completion of a group exercise class. A repeated measures Multivariate Analysis of Variance (MANOVA), with time as the within-subjects factor and leader gender as the between-subjects factor, was conducted. A significant main effect for time was found (F(3, 80) = 19.65, p < 0.001). Estimated marginal means indicated that all participants reported significantly higher SPE and lower SSA and SPA-S post-exercise. Completing an exercise class may override any self-presentational concerns that can arise from the exercise environment. Future studies should adopt ecologically valid research designs to gain a clearer picture of self-presentational concerns in exercise classes.     

Vocal fundamental and formant frequencies affect perceptions of speaker cooperativeness

In recent years, the perception of social traits in faces and voices has received much attention. Facial and vocal masculinity are linked to perceptions of trustworthiness; however, while feminine faces are generally considered to be trustworthy, vocal trustworthiness is associated with masculinized vocal features. Vocal traits such as pitch and formants have previously been associated with perceived social traits such as trustworthiness and dominance, but the link between these measurements and perceptions of cooperativeness have yet to be examined. In Experiment 1, cooperativeness ratings of male and female voices were examined against four vocal measurements: fundamental frequency (F₀), pitch variation (F₀?SD), formant dispersion (D_f), and formant position (P_f). Feminine pitch traits (F₀ and F₀?SD) and masculine formant traits (D_f and P_f) were associated with higher cooperativeness ratings. In Experiment 2, manipulated voices with feminized F₀ were found to be more cooperative than voices with masculinized F₀^, among both male and female speakers, confirming our results from Experiment 1. Feminine pitch qualities may indicate an individual who is friendly and non-threatening, while masculine formant qualities may reflect an individual that is socially dominant or prestigious, and the perception of these associated traits may influence the perceived cooperativeness of the speakers.     

Coping,social support,stigma, and gender difference among people living with HIV in Guangxi,China

The current study examined whether gender, HIV-related stigma, social support, and the interaction between gender and social support are associated with coping responses among people living with HIV and AIDS (PLWHA) in Guangxi, China. A total of 2987 PLWHA in Guangxi participated from October 2012 to August 2013. Multivariate analysis of covariance was conducted with gender and social support as main factors in the model, and stigma and other variables as covariates. After controlling for demographic variables and stigma, there were significant main effects of emotional social support (F = 1.61, p < .001), functional social support (F = 1.67, p < .001), and informational social support (F = 3.67, p < .001) on various coping strategies. The interaction between gender and informational social support (F = 1.33, p < .05), internalized stigma (F = 37.03, p < .001) and perceived stigma (F = 9.16, p < .001) were associated with various coping strategies. Findings signify the importance of HIV-related stigma and social support differences in the coping strategies among PLWHA in Guangxi, China.     

Aggressive interactions and consistency of dominance hierarchies of the native and nonnative cichlid fishes of the Balsas basin

Dominance hierarchies are generally established based on the levels of aggressiveness that animals present. Frequently, animals fight to establish a dominance hierarchy and obtain a disputed resource. The Mexican mojarra Cichlasoma istlanum is a native species of the Balsas river basin and coexists there with four nonnative cichlids: tilapia Oreochromis sp., convict cichlid Amatitlania nigrofasciata, spotcheek cichlid Thorichthys maculipinnis, and green terror Andinoacara rivulatus. These five cichlid species compete for spaces for reproduction, feeding, and shelter and frequently engage in aggressive interactions to obtain these resources. We quantified dominance indices to evaluate the hierarchical structure of dominance among these five cichlids and the duration of aggressive behaviors of the Mexican mojarra during experimental contests between the native species and each of the four nonnative species. The Mexican mojarra was consistently dominant over the other four cichlid species, performing a larger number of aggressive behaviors and investing more time in attacking than the nonnative cichlids, which resulted in a higher hierarchical position. Our results show that the native fish, Mexican mojarra, established dominance over all four nonnative cichlid fish of the Balsas basin. Thus, the establishment of nonnative cichlid species in the Balsas basin is likely associated with factors other than behavioral dominance.     

Dominance structure in small groups of juvenile white-seabream (Diplodus sargus cadenati de la paz,Bauchot and Daget 1974)

Experiments were conducted to investigate the intraspecific aggressive interactions between juveniles of white-seabream (Diplodus sargus cadenati de la Paz, Bauchot and Daget 1974) in relation to dominance hierarchy in small groups. The agonistic interactions between juvenile white-seabream in small groups originated a peck-dominance hierarchy. The dominant (α-fish) generally interacted aggressively and most frequently with the subordinate that was next in line (β-fish) within the dominance hierarchy. This β-fish interacted aggressively more frequently with the γ-fish, and so on. Results demonstrated that fish do not attack subordinates at random. The level of subordination in small groups of juvenile white-seabream was related to body size. Generally, the more aggressive fish manifest a higher growth rate. Aggr. Behav. 24: 197–204, 1998. © 1998 Wiley-Liss, Inc.     

The effect of group status on children's hierarchy-reinforcing beliefs

Members of advantaged groups are more likely than members of disadvantaged groups to think, feel, and behave in ways that reinforce their group's position within the hierarchy. This study examined how children's status within a group-based hierarchy shapes their beliefs about the hierarchy and the groups that comprise it in ways that reinforce the hierarchy. To do this, we randomly assigned children (4–8 years; N = 123; 75 female, 48 male; 21 Asian, 9 Black, 21 Latino/a, 1 Middle-Eastern/North-African, 14 multiracial, 41 White, 16 not-specified) to novel groups that differed in social status (advantaged, disadvantaged, neutral third-party) and assessed their beliefs about the hierarchy. Across five separate assessments, advantaged-group children were more likely to judge the hierarchy to be fair, generalizable, and wrong to challenge and were more likely to hold biased intergroup attitudes and exclude disadvantaged group members. In addition, with age, children in both the advantaged- and disadvantaged-groups became more likely to see membership in their own group as inherited, while at the same time expecting group-relevant behaviors to be determined more by the environment. With age, children also judged the hierarchy to be more unfair and expected the hierarchy to generalize across contexts. These findings provide novel insights into how children's position within hierarchies can contribute to the formation of hierarchy-reinforcing beliefs.

Research Highlights

• A total of 123 4–8-year-olds were assigned to advantaged, disadvantaged, and third-party groups within a hierarchy and were assessed on seven hierarchy-reinforcing beliefs about the hierarchy.
• Advantaged children were more likely to say the hierarchy was fair, generalizable, and wrong to challenge and to hold intergroup biases favoring advantaged group members.
• With age, advantaged- and disadvantaged-group children held more essentialist beliefs about membership in their own group, but not the behaviors associated with their group.
• Results suggest that advantaged group status can shape how children perceive and respond to the hierarchies they are embedded within.

     

Play fighting and the development of agonistic behavior in male and female rats

Two longitudinal studies were conducted to quantify the social behaviors exhibited by both male and female Long-Evans rats from the immediate postweaning period until young adulthood. In Experiment 1, male sibling pairs engaged in a high level of play fighting during the early juvenile period but such activity declined to a level significantly lower than that of female and mixed-sex pairs after 54 days of age. In Experiment 2, social exchanges during maturation were examined during the presence and absence of the piloerection response in an effort to distinguish play fighting from agonistic interactions. In male pairs, piloerection was rarely seen before 55–75 days of age but thereafter occurred with increasing frequency especially among dominant males. Furthermore, subordinate males retreated from their dominant partners and remained in an escape chamber for a significant amount of time only during encounters involving the exhibition of piloerection. This finding suggests that piloerection can be useful in identifying play and aggressive interactions. In female and heterosexual pairs, piloerection was observed infrequently during social encounters occurring throughout maturation. In addition, when given the opportunity to escape, females were less likely to retreat from play activity if their partner was another female than a male.     

Body Image Preference in the United States and Rural Thailand: An Exploratory Study

The authors conducted a field study to examine the female body image preferences of young women and young men in a rural northern province of Thailand and in central California. The Thai participants did not have stronger body image preferences than did the U.S. participants overall. However, the young women preferred a significantly more slender body image than did the young men, F(1, 80) = 14.98, p < .001, and the Respondent Gender x Nationality interaction was also significant, F(1, 80) = 4.42, p = .039. Thai men, as expected, exhibited preferences for figures that were heavier than those preferred by their U.S. counterparts. Thai women, in contrast, exhibited preferences for figures that were thinner than those preferred by their U.S. counterparts or their male countrymen. These results are explained in terms of traditional Thai and U.S. values and in terms of Western cultural influences in modern Thailand.     

Effects of female presence on intrasexual aggression in male lizards,Podarcis hispanicus

Resource value and expected gain in reproduction may affect motivation to fight and the likelihood of winning. Previous experiments have showed that males increase their fighting effort when defending a territory that contains females. However, we hypothesized that for an intruding lizard, the value of a new territory may be lower if he already has a female in his own territory, and consequently, aggressivity should be lesser than if he has no access to any female. We staged encounters between males of the lizard Podarcis hispanicus in outdoor terraria to analyze the outcome and detailed behaviors involved in agonistic interactions in the presence or absence of a female in the terraria of resident and intruders. Our results showed that when a female was present, the level of aggressivity of the resident male was higher; the probability of winning the contest also increased, but only if the intruding male had no females in his own terraria. In contrast, when the intruding male was also the owner of another territory containing a female, residents were less aggressive. We suggest that the lack of information on the reproductive state of an unfamiliar female may be enough to decrease fighting motivation of an intruding male, if he has more expectations of success with his own familiar female. We conclude that differences in expected reproductive success with different females may help to decide the outcome of conflicts between males quicker and cheaper. Aggr. Behav. 28:491–498, 2002. © 2002 Wiley‐Liss, Inc.     

Relational and Social Aggression and Reflective Processing in a University Sample

This study examined whether the dimension of reflective processing (e.g., deep and elaborative processing) was connected to the use of relational aggressions, social aggression, or both. A convenience sample of 629 college students (66% female, 91.6% White) was surveyed to ascertain the relation between self-reported relational and social aggression and deep and elaborative processing. The overall multivariate regression model was significant, Wilks’s λ = .12, F(4, 2162) = 1010.80, p < .001. Univariate results were used to show that the two predictors (relational and social aggression) significantly and strongly positively predicted the use of deep processing, R² = .81, p < .001, as well as the use of elaborative processing, R² = .87, p < .001. In summary, higher levels of social and relational aggression were related to higher levels of deep and elaborative processing. Implications for these findings are presented.     

Relational aggression in college students: Examining the roles of social anxiety and empathy

This study examined the unique contributions of social anxiety and empathy to relational aggression in 300 19–to–25–year–old (M=21.25; SD=1.32) male (n=97) and female (n=203) college students using hierarchical linear regression analysis. The interactive relations between gender and social anxiety, and between gender and empathy, were also assessed. In addition to the gender and overt aggression covariates, fear of negative evaluation and perspective taking were unique predictors of relational aggression. Males, students who were more overtly aggressive, and those who reported greater fear of negative evaluation were more relationally aggressive than were peers. Students with higher levels of perspective taking reported using less relational aggression than did peers. A gender x empathetic concern interaction indicated that for males only, lower levels of empathetic concern were associated with higher levels of relational aggression. Results are discussed within a social information‐processing perspective. Aggr. Behav. 29:430–439, 2003. © 2003 Wiley‐Liss, Inc.