Variability of responding on a concurrent schedule as a function of body weight

Five pigeons pecked for food reinforcers on a concurrent variable-interval one-minute, variable-interval four-minute schedule. Each bird's body weight was varied from 80% of its free-feeding weight to 95% and then by 5% steps to 110% or until weight gains ceased. The coefficient of variation, but not the standard deviation, of the daily rate of responding on each of the component schedules increased with increases in body weight.     

Effects of Undergoing Arbitrary Discrimination Upon Subsequent Attitudes Toward a Minority Group1

The purpose of the experiment was to test the hypothesis that having been both the object of prejudice and discrimination and the discriminator, a child will be less likely to hold prejudiced beliefs and exhibit discriminatory behavior toward a minority group. A 3rd-grade class was randomly divided into Orange and Green people. On Day I, Orange children were “superior” and Green children were “inferior”. On Day II, statuses were rcvcrsed. On Day III and again 2 weeks later, the experimental class was significantly more likely to desire a picnic with a group of Black children and held less-prejudiced beliefs when compared to the Control. The manipulation did not affect performance on Days I and II.     

Sex stereotypes and implicit personality theory. II. A trait-inference approach to the assessment of sex stereotypes

Two experiments were conducted to assess sex stereotypes using the trait-inference method originated by Asch (1946). In both, subjects were asked to make inferences about the personality of a male or a female stimulus target who was introduced by a brief list of traits. In Experiment 1 this trait list described the target as either good or bad in intellectual activities and as either warm or cold while in Experiment 2 the introductory list comprised traits which are relatively neutral in terms of evaluation. Subjects rated the stimulus persons on adjective scales selected to reflect dimensions of personality perception reported in previous research. In both studies, male targets were rated significantly higher than females in terms of the Intellectual Desirability dimension. In addition, female targets tended to be rated higher on Communion in Experiment 1 (p<.06), and lower than males on Potency in Experiment 2 (p<.07). No differences as a function of stimulus sex were obtained for Social Desirability, Activity, and Agency. The results suggest that the dimension of implicit personality theory most closely associated with perceived sex differences is a combination of Intellectual Desirability and Potency. The male end of this dimension is relatively well defined by traits which convey a hard-headed, rational approach to problem solving. The female end is much less elaborated and consists of traits reflecting soft-heartedness.     

The MCMI as a measure of DSM-III

The Millon Clinical Multiaxial Inventory (MCMI) has been interpreted as a measure of DSM-III disorders. However, the MCMI was constructed and validated primarily as a measure of Millon's (1969, 1981) taxonomy, not DSM-III. Comparison of the two taxonomies and examination of the MCMI's content validity for two of the MCMI scales indicate only a partial congruence between the Millon and DSM-III taxonomies. There has been no published empirical research concerning the relationship between the MCMI and DSM-III, and the derivation and cross-validation research for the MCMI scales employed Millon's taxonomy and not DSM-III. It is suggested that until such data have been presented one should be cautious in one's interpretation of the MCMI as a measure of DSM-III disorders.     

Mapping the Growth of Heterogeneous Forms of Externalizing Problem Behavior Between Early Childhood and Adolescence:A Comparison of Parent and Teacher Ratings

We compared long-term growth patterns in teachers’ and mothers’ ratings of Overt Aggression, Covert Aggression, Oppositional Defiance, Impulsivity/inattention, and Emotion Dysregulation across developmental periods spanning kindergarten through grade 8 (ages 5 to 13 years). We also determined whether salient background characteristics and measures of child temperament and parenting risk differentially predicted growth in discrete categories of child externalizing symptoms across development. Participants were 549 kindergarten-age children (51% male; 83% European American; 17% African American) whose problem behaviors were rated by teachers and parents each successive year of development through 8th grade. Latent growth curve analyses were performed for each component scale, contrasting with an overall index of externalizing, in a piecewise fashion encompassing two periods of development: K-1and grades 1–8. Our findings showed that there were meaningful differences and similarities between informants in their levels of concern about specific forms of externalizing problems, patterns of change in problem behavior reports across development, and in the extent to which their ratings of specific problems were associated with distal and proximal covariates. Thus, these data provided novel information about issues that have received scant empirical attention and have important implications for understanding the development and prevention of children’s long-term externalizing problems.     

Effects of harsh parenting and positive parenting practices on youth aggressive behavior: The moderating role of early pubertal timing

Prior research indicates that early pubertal timing is associated with aggressive behavior, particularly in the context of adversity as postulated in the contextual amplification hypothesis. However, few studies have examined harsh parenting as the context for the effect of early pubertal timing. Even fewer studies have tested the interactive effect of early pubertal timing and positive parenting on aggressive behavior. In this study, we tested the proposition that early pubertal timing, contrary to the general conception of it as a vulnerability, indexed susceptibility, and thus early maturing individuals were affected more by their environment in a “for better and for worse” manner. The sample consisted of 411 community‐recruited youth aged 11–12 years (51% boys, 80% African Americans). Participants reported Tanner Stages of pubertal development, aggressive behavior and harsh parenting practice of their parents. Puberty scores were standardized with groups of the same age, sex, and ethnicity, and those that scored the top one‐third were defined as early maturing individuals. Parents reported youth's aggressive behavior and their parenting practices towards the youth, including harsh parenting and positive parenting. Early pubertal timing significantly moderated the relationship between harsh/positive parenting and aggressive behavior. Specifically, harsh parenting was positively associated with aggressive behavior to a larger degree among early maturing individuals than among on‐time/late‐maturing individuals. Positive parenting was inversely associated with aggressive behavior but only among early maturing individuals. This study is the first to document support for early pubertal timing as susceptibility to the environmental influences in relation to aggressive behavior. Theoretical and intervention implications are discussed.