IS AGE IMPORTANT? TESTING A GENERAL VERSUS A DEVELOPMENTAL THEORY OF ANTISOCIAL BEHAVIOR*

We tested competing hypotheses derived from Gottfredson and Hirschis (1990) general theory and Moffitt's (1993a) developmental theory of antisocial behavior. The developmental theory argues that different factors give rise to antisocial behavior at different points in the life course. In contrast, the general theory maintains that the factor underlying antisocial behavior (i.e., criminal propensity) is the same at all ages. To test these competing predictions, we used longitudinal data spanning from age 5 to age 18 for the male subjects in the Dunedin Multidisciplinary Health and Development Study. Using reports from three sources (parents, teachers, and the boys themselves), we estimated second-order confirmatory factor models of antisocial behavior. These models provided consistent support for the developmental theory, showing that separate latent factors underlie childhood and adolescent antisocial behavior. Moreover, we found that these childhood and adolescent factors related in ways predicted by Moffitt's developmental theory to four correlates of antisocial behavior: Childhood antisocial behavior was related more strongly than adolescent antisocial behavior to low verbal ability, by per activity, and negative/impulsive personality, whereas adolescent antisocial behavior was related more strongly than childhood antisocial behavior to peer delinquency. The two underlying latent factors also showed the predicted differential relations to later criminal convictions: Childhood antisocial behavior was significantly more strongly associated with convictions for violence, while adolescent antisocial behavior was significantly more strongly associated with convictions for nonviolent offenses.     

Scanning electron microscopy: application in the identification of diatoms in cases of drowning.

A simple and rapid method is described for processing organ and water samples for the identification of diatoms so that they can be studied and recorded for taxonomic and diagnostic purposes. Samples are treated with concentrated nitric acid; the fluid obtained is centrifuged, and its sediment is dried, coated, and examined under the scanning electron microscope. The method does not alter the morphology of diatoms and allows the study of freshwater and seawater species present in the organs of bodies found in the water, making possible the diagnosis of drowning under specific conditions.