The role of endocrines in isolation-induced lntermale fighting in albino laboratory mice. II. Sex steroid influences in aggressive mice

Isolation-induced intermale fighting in laboratory mice can be dramatically reduced under most circumstances by castration. This behavior in castrates may, however, be restored, or even accentuated, by androgen replacement. Experiments on the effects of sex steroids on such fighting in castrated mice, which, for want of a better term, are designated as “aggressive,” have been recently described. These mice are housed with a female until 10 days after siring a litter and are, thereafter, housed individually for a further 14 days before castration and subsequent hormone treatment. Such mice show substantial levels of fighting in “standard-opponent” tests even before isolation. Although castration results in reduced fighting in these mice, this behavior is rarely completely abolished in all individuals. It seems likely that steroid treatment of aggressive mice maintains or intensifies an already present motivation. Treatments in these studies consisted of daily oil-based intramuscular injections for 14 days preceding and throughout behavioral testing. The standard-opponent tests were 7 min encounters with adult, subordinate, grouped males in the cleaned home cages of experimental mice. The steroids investigated included estradiol benzoate (EB), 19-hydroxytestosterone (19-OHT), androstenedione (A), testosterone (T), and Sα-dihydrotestosterone (DHT), either singly or in combination. The results suggest that (a) on a dosage basis, estrogens were at least as effective as androgens in maintaining fighting in castrated aggressive mice; (b) 19-OHT (one of the metabolic intermediates between testosterone and 17 β-estradiol) was also effective but somewhat less so than the same dose of EB; (c) the three naturally occurring androgens investigated all effectively maintained fighting at comparatively low doses (50 μg/day) which compares with a replacement dose of 500 μg/day of T in some studies in traditional castrated mice (e.g., Luttge and Hall, 1973); (d) aromatization is not essential for a behavioral action of androgens as DHT, a nonaromatizable androgen, maintained fighting in these mice; (e) whereas a two-site (central motivational and peripheral penile) action seems probable in the influence of androgens on sexual behavior in castrated rats (e.g., Parrott, 1975), DHT did not augment the action of EB on fighting in castrated aggressive mice, indicating that only a central action of steroids was required in the aggressor.     

The introduction of a group of alien mice (Mus musculus L.) into hierarchically organized groups of five male mice

Groups of 3 male or female Mus musculus were introduced into hierarchically organized colonies of 5 male mice for a period of 8 days. The colonies were of 2 kinds; high-level aggressive (HLA), which had been set up 3 days prior to the introduction of the aliens, and low-level aggressive (LLA), which had been established for 21 days before strangers were introduced. Both males and anestrous females were attacked, but males were attacked 5 times more frequently than females. In HLA colonies most of the attacks on the aliens were by the dominant; in LLA colonies there was no difference in the behavior of dominant and subordinate mice toward strangers. Both aggression toward aliens and intracolony aggression declined over the 8 day experimental period. In HLA colonies the dominant mouse mounted females 5 times more frequently than did either his subordinates or male mice in the LLA colonies. In HLA colonies aliens huddled with subordinates to form a single colony with 1 dominant and 7 subordinates. In LLA colonies alien males remained as a discrete group spatially separated in the cage. Female aliens were incorporated into the main colony. In all cases dominant male mice made more attacks on aliens as compared with familiar mice.     

Trajectories of Social Anxiety in Children: Influence of Child Cortisol Reactivity and Parental Social Anxiety

Few studies have examined the interactive effect of intra- and extra-individual vulnerability factors on the trajectory of social anxiety in children. In this study, we examined the joint influence of familial vulnerability (i.e., parental social anxiety) and child biological stress vulnerability (i.e., cortisol reactivity) on trajectories of social anxiety. Children (N?=?112 (57 males), M _age?=?8.14 years, S.D. = 2.25) were followed over three visits spanning approximately three years. Parental social anxiety was assessed using the Social Phobia and Anxiety Inventory, children’s behavior and salivary cortisol reactivity were measured in response to a speech task, and children’s social anxiety was assessed at all three visits using the Screen for Child Related Emotional Disorders (SCARED; Parent-report). A growth curve analysis was used to examine trajectories of child social anxiety as predicted by children’s cortisol reactivity and parental social anxiety, adjusting for covariates. We found a significant interaction between parental social anxiety and child cortisol reactivity in predicting child social anxiety across time. Having a socially anxious parent coupled with heightened cortisol reactivity predicted the highest levels of child social anxiety, with scores that remained above clinically significant levels for social anxiety across all visits. Children with familial risk for social anxiety and who also exhibit high stress-reactivity appear to be at risk for persistent, clinically significant social anxiety. This highlights the importance of considering the interaction between both biological and contextual factors when considering the development, maintenance, and treatment of social anxiety in children across time.     

Racial Prototypicality,Affirmative Action,and Hiring Decisions in a Multiracial World

This research examined how the racial prototypicality of minority job applicants' faces influenced hiring decisions under different affirmative action (AA) policies: no AA, soft AA (recruitment of minorities with merit‐based hiring), and hard AA (race as a tie‐break factor in hiring). Participants (N=252) evaluated resume/photograph pairs, each containing a Caucasian and a Black applicant, with minority applicants representing three levels of racial prototypicality. The number of jobs awarded to minorities increased as Black racial prototypicality increased. Each level of AA policy strength increased the number of minority hires, but these increases came with a price: AA directives decreased the percentage of minority hires attributed to higher qualifications and increased perceptions that hires were due to AA more than was actually the case.     

How Readability Shapes Social Media Engagement

We suggest that text readability plays an important role in driving consumer engagement on social media. Consistent with a processing fluency account, we find that easy‐to‐read posts are more liked, commented on, and shared on social media. We analyze over 4,000 Facebook posts from Humans of New York, a popular photography blog on social media, over a 3‐year period to see how readability shapes social media engagement. The results hold when controlling for photo features, story valence, and other content‐related characteristics. Experimental findings further demonstrate the causal impact of readability and the processing fluency mechanism in the context of a fictitious brand community. This research articulates the impact of processing fluency on brief word‐of‐mouth transmissions in the real world while empirically demonstrating that readability as a message feature matters. It also extends the impact of processing fluency to a novel behavioral outcome: commenting and sharing actions.     

Working memory capacity and the top-down control of visual search: Exploring the boundaries of "executive attention"

The executive attention theory of working memory capacity (WMC) proposes that measures of WMC broadly predict higher order cognitive abilities because they tap important and general attention capabilities (R. W. Engle & M. J. Kane, 2004). Previous research demonstrated WMC-related differences in attention tasks that required restraint of habitual responses or constraint of conscious focus. To further specify the executive attention construct, the present experiments sought boundary conditions of the WMC-attention relation. Three experiments correlated individual differences in WMC, as measured by complex span tasks, and executive control of visual search. In feature-absence search, conjunction search, and spatial configuration search, WMC was unrelated to search slopes, although they were large and reliably measured. Even in a search task designed to require the volitional movement of attention (J. M. Wolfe, G. A. Alvarez, & T. S. Horowitz, 2000), WMC was irrelevant to performance. Thus, WMC is not associated with all demanding or controlled attention processes, which poses problems for some general theories of WMC.     

Sex roles,social roles,and clinical judgments of mental health

This study examined whether clinical psychologists expect similar behavior from males and females in contexts that are traditionally male vs. female. In a modification of the task by Broverman et al. (Journal of Consulting and Clinical Psychology, 1970, 34, 1–7), practicing psychologists (N=104) rated the appropriate behavior of a mature, healthy, socially competent man in the home environment, man in the work environment, woman in the home environment, or woman in the work environment. There was a significant effect of environment, with ratings closer to the pole traditionally labeled masculine in the work environment (p<.001). However, clinicians did not assign significantly different ratings to men vs. women. These data call into question the continued use of feminine and masculine to describe behavior, and emphasize the need to specify the environmental context in research on sex role stereotypes.This report is based on an undergraduate honors thesis conducted by the second author under the sponsorship of the first. Order of authorship is alphabetical.