Relative contributions of aggression and reproduction to behavioral endocrinology

Reproductive activity has been the behavior of choice for research in behavioral endocrinology. Why this is so and the consequences to the study of aggression and to behavioral endocrinology in general are explored.     

An evaluation of contingency strength and response suppression

Typically, functional analyses of severe problem behavior have been conducted in two ways: (a) The target response is reinforced immediately after it occurs, or (b) the target response is reinforced on some schedule thought to mimic a naturally occurring schedule. We evaluated the effects of contingency strength in reducing levels of problem behavior with 2 participants who had been diagnosed with developmental disabilities. Results showed that under a neutral contingency, one in which the probability of reinforcement for aggression was equal to the probability of reinforcement for the nonoccurrence of aggression, rates of aggression were suppressed to low levels for both participants.     

Do Positive Self-Perceptions Have a “Dark Side”? Examination of the Link between Perceptual Bias and Aggression

The hypothesis that positive self-perceptions may have a dark side was investigated in the present study by examining the relationship between positively biased self-perceptions and aggression. Ratings of actual and perceived social acceptance of third-grade (n = 278), fourth-grade (n = 260), and fifth-grade (n = 321) students were compared to form a measure of perceptual bias. Peers provided nominations for overt and relational aggression. Gender differences were found for aggression (males were more overtly and relationally aggressive than females) but not perceptual bias. African-American children held more positive perceptions of their social acceptance and were perceived by peers as more aggressive than Caucasian children. Even after controlling for the effects of gender and ethnicity, more positively biased perceptions were associated with more peer nominations for overt and relational aggression. Contrary to an optimal range of bias hypothesis, even moderately positive self-perceptions were associated with elevated levels of aggression.     

The Relation of Perceived Neighborhood Danger to Childhood Aggression: A Test of Mediating Mechanisms

In the current study, two mediational mechanisms, parenting practices and children's beliefs about aggression, were hypothesized to account for the relationship between perceived neighborhood danger and childhood aggression. Using structural equation modeling, data were analyzed from an inner-city school-based sample of 732 predominantly African American 5th graders. Results suggested that perceived neighborhood danger was associated with strong positive beliefs about aggression, which in turn was associated with high levels of aggression. The hypothesized mediating role of parenting practices (restrictive discipline, parental monitoring, and parental involvement) on the relation between perceived neighborhood danger and child aggression was not supported. However, the current findings suggest that children's positive beliefs about aggression mediated the relationship between restrictive discipline and aggression. Directions for future research are discussed.     

Trajectories of Peer-Nominated Aggression: Risk Status,Predictors and Outcomes

Developmental trajectories of peer-nominated aggression, risk factors at baseline, and outcomes were studied. Peer nominations of aggression were obtained annually from grades 1 to 3. Three developmental trajectories were identified: an early-onset/increasers trajectory with high levels of peer-nominated aggression at elementary school entry and increasing levels throughout follow-up; a moderate-persistent trajectory of aggression in which children were characterized by moderate levels of physical aggression at baseline; and a third trajectory with stable low levels of aggression. Children following the early-onset/increasers trajectory showed physical forms of aggression at baseline. Male gender and comorbid attention deficit/hyperactivity problems, oppositional defiant problems and poor prosocial behavior plus negative life events predicted which children would follow the early-onset/increasers trajectory of aggression. The outcomes associated with the early-onset/increaser children suggest high risk for chronically high levels of aggressive behavior.     

Is Workplace Harassment Hazardous to Your Health?

We examined cross-sectional and lagged effects of sexual harassment (SH) and generalized workplace harassment (GWH) on incidence of self-reported illness, injury, or assault in a sample of over 1,500 university employees. SH and GWH, but not other job stressors, were related to increased odds of illness, injury, or assault. This was true when SH, GWH, and illness, injury, or assault were measured at the same time point, as well as when SH and GWH were measured in year prior to illness, injury, or assault.The data presented here are part of an ongoing longitudinal study of workplace harassment conducted at the Department of Psychiatry of the University of Illinois at Chicago. This research was supported by the National Institute on Alcohol Abuse and Alcoholism (grants AA09989 and AA13332). Portions of this paper were presented at the annual meeting of the Society for Industrial and Organizational Psychology, April 2004, Chicago, Illinois. The data were collected by the Survey Research Laboratory at the University of Illinois at Chicago.     

Heart Follows Head: Influencing Violence-related Attitudes in the Classroom

We examined whether an undergraduate course on violence would influence students’ violence-related attitudes and beliefs. Students (N=145) completed the Violence-Related Attitudes and Beliefs Scale (V-RABS) at the beginning (Time 1) and end (Time 2) of the semester-long course. As expected, support for the death penalty, punishment, and catharsis decreased significantly, as did belief in an association between mental illness and violence. Acceptance of environmental influences on violent behavior increased significantly, although belief in biological influences did not change. Support for violence prevention efforts was high at both Times 1 and 2, and did not change significantly. Consistent with previous research, the results of this study confirm that college curricula may influence students’ attitudes and beliefs in addition to imparting knowledge.     

Effect of Children's Perceived Rejection on Physical Aggression

This study investigated whether the perception of self as socially rejected might contribute to increased physical aggression among elementary-school children. It was hypothesized that physically aggressive children would become more physically aggressive over time if they perceived that they were rejected and tended to blame peers for social failure experiences. Third-grade boys and girls (n = 941) were assessed in the Fall and Spring of the school year. Peer-report data on physical aggression and social preference were collected, along with self-report data on perceived rejection and attributions for social failure experiences. Results for boys were consistent with hypotheses, whereas the results for girls revealed a different pattern of relations. These results constitute prospective evidence that children's self-perceptions of social rejection can uniquely influence externalizing behavior. Results are discussed in terms of mechanisms that might mediate the relation between perceived rejection and physical aggression.     

Choosing or Being Chosen by Aggressive–Disruptive Peers: Do They Contribute to Children's Externalizing and Internalizing Problems?

The goal of this study was to investigate the extent to which aggressive-disruptive peers contribute to the development of externalizing and internalizing problems in children, while controlling for children's own behavior. We examined 2 sets of peers: (1) those that the child nominated as friends, and (2) those that nominated the child as a friend. The participants were 236 boys and girls attending 3rd to 5th grade at the beginning of the study, who were followed over a period of 2 years. Results showed that choosing more aggressive peers on the nomination procedure was associated with more externalizing problems and self-reported depressive symptomatology over time. On the other hand, being liked by more aggressive children generally was not associated with elevated externalizing or internalizing problems.