Genetic and ontogenetic determinants of adult behavior in the rat

Abstract

80 rats from the Maudsley Reactive and Nonreactive Strains, selected for emotional defecation, were subjected to controlled infantile stimulation. When adult, they were tested for open-field emotionality and escape-avoidance conditioning in a factorial design, which included strain, treatment, sex, and test-order variables. Both heredity and environment had significant effects, and also display interaction. The scores from the open-field showed that infantile stimulation caused a significant decrease in emotionality indexes which is attributed to a change in the capacity to respond to stress. The reactive strain was significantly poorer in escape-avoidance conditioning. (17 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1963 American Psychological Association.