The development of boys' preferential pleasure in physical aggression.

A large body of literature on physical aggression focuses on its maladaptive nature and causes. The current study of 335 children (209 boys, 126 girls), aged 4-, 5-, 6-, and 9-years, examined a different facet of harmful physical aggression-the development of the pleasure it provides to boys. Two samples of children were included, first 89 boys, then an additional 120 boys and 126 girls. For the first two free response measures, all 209 boys and 126 girls were asked to describe how they played with their three favorite toys and their three favorite playmates, and these descriptions were coded for the presence of physical aggression. Twelve additional structured measures were administered to the second sample of 120 boys and 126 girls. These children were asked to rate how much they enjoyed enacting and viewing on television physical aggression, non-physically aggressive male sex-typed roles, and ambiguously sex-typed roles. Results demonstrated that approximately 50% of boys at all four age levels (and less than 10% of girls) reported that at least one of their three favorite toys was used for inflicting harm through physical aggression on an animate being. Further, with increasing age, boys rated physical aggression in play activities and on television as more enjoyable than alternative male sex-typed play and television content. Results suggest that advancing understanding of the development of physical aggression requires acknowledging the pleasure it provides to males.

Counterintuitive and alternative moves choice in the Water Jug task.

MOVE problems, like the Tower of London (TOL) or the Water Jug (WJ) task, are planning tasks that appear structurally similar and are assumed to involve similar cognitive processes. Carder et al. [Carder, H.P., Handley, S.J., & Perfect, T.J. ( 2004). Deconstructing the Tower of London: Alternative moves and conflict resolution as predictors of task performance. The Quarterly Journal of Experimental Psychology 57a, 8, 1459-1483] showed that one predictor of TOL performance was the number of alternative move choices there were at a given point in the solution. In two experiments an individual move experienced on the WJ task was manipulated (perceptually consistent/counterintuitive) along with the number of alternative moves there were to choose between. A verification paradigm was employed in which participants made speeded judgements about the correctness of a move. Results showed performance was consistent with the application of a perceptual strategy accompanied by a process involving the evaluation of non-redundant alternative moves. These are discussed in the context of recent research that has examined the impact of executive dysfunction on Water Jug performance [Colvin, M.K., Dunbar, K., & Grafman, J. (2001). The effects of frontal lobe lesions on goal achievement in the Water Jug task. Journal of Cognitive Neuroscience, 13, 1129-1147].

Explaining sex differences in infants' preferences for groups.

Social organization of a species influences myriad facets of individuals' behavior. Much research indicates that human social organization consists of males in large groups and females in smaller groups or interacting with individuals. This study analyzed the initial factors that produce greater preferences for groups by human male versus female infants. To this end, using a looking preference paradigm, fifty-nine 6-8-month-old infants viewed individual versus group images of actual children. On the basis of several controls, results demonstrated that male more than female infants are attracted to the complex level of stimulation provided by groups. Discussion centers on further identifying male versus female patterns of group interaction from a perceptual and cognitive standpoint.