"This investigation was concerned with the effects of infantile trauma upon adult temperament, the influence of genetic factors upon temperament, and the possibility of an interaction between early experience and gene structure in their influence upon adult behavior." With mice as the Ss, evidence was obtained which indicated that: genetic factors influence emotionality, timidity, and motility in mice; infantile trauma influences emotionality; and there is an interaction effect of genetic and traumatic factors on timidity. The results are related to Freudian theory. (20 ref.) (PsycINFO Database Record (c) 2006 APA, all rights reserved)