Levels of abstraction in orangutan (Pongo abelii) categorization

Levels of abstraction have rarely been manipulated in studies of natural concept formation in nonhumans. Isolated examples have indicated that animals, relative to humans, may learn concepts at varying levels of abstraction with differential ease. The ability of 6 orangutans (Pongo abelii) of various ages to make natural concept discriminations at 3 levels of abstraction was therefore investigated. The orangutans were rewarded for selecting photos of orangutans instead of humans and other primates (concrete level), primates instead of other animals (intermediate level), and animals instead of nonanimals (abstract level) in a 2-choice touch screen procedure. The results suggest that, like a gorilla (Gorilla gorilla gorilla) tested previously (Vonk & MacDonald, 2002), orangutans can learn concepts at each level of abstraction, and unlike other nonhumans, most of these subjects rapidly learned the intermediate level discrimination.     

An assessment of generalization of imitation in two enculturated orangutans (Pongo pygmaeus)

Deferred imitation of object-related actions and generalization of imitation to similar but not identical tasks were assessed in two human-reared (enculturated) orangutans (Pongo pygmaeus). Each ape displayed low levels of deferred imitation but did not provide evidence of generalization of imitation. Results suggest that enculturated orangutans may not possess social-cognitive abilities similar to that which enculturated chimpanzees are assumed to possess.     

Rejected bullies or popular leaders? The social relations of aggressive subtypes of rural african american early adolescents

Teacher assessments of interpersonal characteristics were used to identify subtypes of rural African American early adolescents (161 boys and 258 girls). Teacher ratings of interpersonal characteristics were used to identify popular and unpopular aggressive subtypes for both boys and girls. Unpopular aggressive youths did not have elevated levels of rejected sociometric status but were more likely to have lower levels of peer-perceived social prominence and social skills. Conversely, popular aggressive youths were more likely to be disliked by peers even though they were perceived by peers as socially prominent and socially skilled and were identified by teachers as highly involved in extracurricular activities. Both popular and unpopular aggressive youths tended to associate with others who had similar levels of peer-perceived popularity.     

Recombinative generalization of within-syllable units in nonreading adults with mental retardation

Two adults with mental retardation demonstrated the recombination of within-syllable units (onsets and rimes) using a spoken-to-printed-word matching-to-sample (MTS) procedure. Further testing with 1 participant showed comprehension of the printed words. Printed-word naming was minimal before, but greater after, comprehension tests. The findings suggest that these procedures hold promise for further basic and applied analyses of word-attack skills.     

The Life Attitudes Schedule-Short Form: psychometric properties and correlates of adolescent suicide proneness

The goals of the present study were to describe the psychometric properties of the Life Attitudes Schedule-Short Form (LAS-SF) in adolescents and provide criterion and construct validity data, including bivariate and multivariate associations with related risk behaviors. Anonymous questionnaires containing the LAS-SF and related measures were administered to 1,742 high school students in three states. Psychometric properties for LAS-SF items and total score were very good, and the LAS-SF was correlated with almost all of the examined risk behaviors, illustrating the broad range of problems measured by the instrument. LAS-SF total scores were associated with past suicide attempt, even after controlling for the impact of current depression. Clinical and research uses for the LAS-SF are discussed.     

Multidimensional Personality Questionnaire profiles of veterans with traumatic combat exposure: externalizing and internalizing subtypes

This study used the Multidimensional Personality Questionnaire (MPQ; A. Tellegen, in press) to identify personality-based subtypes of posttraumatic response. Cluster analyses of MPQs completed by combat veterans revealed subgroups that differed on measures relating to the externalization versus internalization of distress. The MPQ profile of the externalizing cluster was defined by low Constraint and Harmavoidance coupled with high Alienation and Aggression. Individuals in this cluster also had histories of delinquency and high rates of substance-related disorder. In comparison, the MPQ profile of the internalizing cluster was characterized by lower Positive Emotionality, Alienation, and Aggression and higher Constraint, and individuals in this cluster showed high rates of depressive disorder. These findings suggest that dispositions toward externalizing versus internalizing psychopathology may account for heterogeneity in the expression of posttraumatic responses, including patterns of comorbidity.     

Mothers' and fathers' depressive symptoms and conflict-resolution strategies in the marriage and children's externalizing and internalizing behaviors

The authors examined mothers' and fathers' avoidance and attacking conflict-resolution strategies in the marriage and their depressive symptoms as they related to children's externalizing and internalizing behaviors. A nonclinical community sample of 51 families and their children's 1st-grade teachers (N = 41) participated. Both mothers and teachers completed a behavior-problem checklist in order to evaluate the incidence of internalizing and externalizing behaviors in the children. Correlational statistics revealed significant associations between parents' avoidance and attacking strategies and their depressive symptoms. Also, parents' use of avoidance was related to more internalizing behaviors in the children. When hierarchical regression analyses were used to examine the contributions of the parents' attributes to children's externalizing and internalizing behaviors, mothers' avoidance and an interaction between mothers' and fathers' avoidance were identified as significant predictors of children's internalizing behaviors.