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.     

Birth month and suicide among major league baseball players

We examined the association between month of birth and completed suicides among major league baseball players (N = 76). More than twice as many players born in August committed suicide (N = 19) than any other birth month. This association was statistically significant when birth month was corrected for differences in days of the month. The differences were even larger when expressed in terms of birth month for those committing suicides divided by number of major league players born in each month. The association between birth month and suicide raises the possibility that prenatal factors may influence the inclination for suicide later in life.     

Educational attainment and suicide rates in the United States

We examined the relationship between educational attainment and suicide rate in the United States for 2001. Suicide rates, adjusted for age, were compared with percentage of college graduates, median household income, and poverty in 50 states in 2001. The correlations of suicide rates with educational attainment and median household income were both negative and statistically significant. Poverty was not significantly related to suicide rates. We concluded that higher education and income were associated with a decrease in suicide rates in 2001. Data from other years require examination for this conclusion to be generalizable.     

Assessing aggression in adolescent romantic relationships: can we do it better?

Almost all research on aggression in adolescent romantic relationships makes use of 1-time, retrospective assessment methods. In the present research, the authors compared data on the experience of adolescent relationship aggression (physical aggression and threatening behavior) collected from 125 high school students via 2 methods: (a) a 1-time, 2-month retrospective assessment and (b) a cumulative method based on four 2-week retrospective assessments, each spaced 2 weeks apart. For the cumulative method, data from the 4 assessments were aggregated to cover the same time period as the single, 2-month retrospective assessment. A greater proportion of the sample (48.0%) reported experiencing physical aggression using the cumulative method compared with the single, 2-month retrospective method (27.0%). The prevalence of threatening behavior was also higher using the cumulative method (48.8% vs. 24.8%). Adolescent trauma and anxiety symptoms correlated more strongly with physical aggression data derived from the cumulative method than from the 1-time assessment method.     

Children's questions about interparent conflict and violence: what's a mother to say?

This research examined the relation between mothers' responses to children's questions about interparent conflict and children's adjustment. Participants were 134 mothers and their children (70 boys, 64 girls), aged 7 to 10. In each family, an act of intimate-partner violence (IPV) had recently occurred. Mothers' responses to children's questions about interparent conflict were assessed via a semistructured interview coded to reflect the extent to which the mothers' responses addressed the content of the children's questions. Mothers and children reported on physical IPV. Mothers also reported on interparent conflict, parent-child aggression, and maternal warmth. Children's adjustment was assessed via mothers' and children's reports at two time points 6 months apart. The extent to which mothers' responses addressed the content of the children's questions about interparent conflict was negatively associated with children's adjustment problems, after accounting for the frequency of physical IPV, frequency of interparent conflict, parent-child aggression, and maternal warmth. These associations emerged cross-sectionally and prospectively. However, in those prospective analyses that accounted for children's baseline levels of adjustment, maternal responsiveness was not associated with later children's adjustment problems.     

An evaluation of the consequences of using short measures of the Big Five personality traits

Researchers often use very abbreviated (e.g., 1-item, 2-item) measures of personality traits due to their convenience and ease of use as well as the belief that such measures can adequately capture an individual's personality. Using data from 2 samples (N = 437 employees, N = 355 college students), we show that this practice, particularly the use of single-item measures, can lead researchers to substantially underestimate the role that personality traits play in influencing important behaviors and thereby overestimate the role played by new constructs. That is, the use of very short measures of personality may substantially increase both the Type 1 and Type 2 error rates. We argue that even slightly longer measures can substantially increase the validity of research findings without significant inconvenience to the researcher or research participants.     

Effects of a Parenting Intervention on Features of Psychopathy in Children

This study examined whether Project Support, a parenting intervention shown to reduce child conduct problems, also exerts positive effects on features of psychopathy in children. Participants were 66 families (mothers and children) recruited from domestic violence shelters who participated in a randomized controlled trial evaluating Project Support. Each family included at least one child between the ages of 4 and 9 who was exhibiting clinical levels of conduct problems. Families were randomly assigned to the Project Support intervention condition or to an existing services comparison condition, and they were assessed on 6 occasions over 20 months, following their departure from the shelter. Children in families in the Project Support condition, compared with those in the comparison condition, exhibited greater reductions in features of psychopathy. Moreover, the changes in features of psychopathy remained after accounting for changes in conduct problems. Project Support’s effects on features of psychopathy were mediated by improvements in mothers’ harsh and inconsistent parenting. These findings on the effects of an intervention on features of psychopathy are the first from a randomized controlled trial. They inform the debate about whether features of psychopathy in children are responsive to intervention, and hold important implications for clinical practice.