Social-seeking and novelty-seeking behavior as a function of differential rearing histories.

Rats were handled daily from birth until weaning or were nonhandled controls. At weaning Ss were reared with littermates or in isolation. At 90 days some of the socially reared Ss were placed into isolation. Total N = 44 males, 1 from each of 44 different litters. At 100 days S was placed for 10 min. into the stem of a T shaped unit. S could remain where it was, enter a social chamber, or enter a novel chamber. Time in each chamber, activity, and defecation were recorded for 4 successive days. Handled Ss were significantly more active, and spent significantly more time in the social and novel chambers than nonhandled controls. Ss reared in a social environment until testing spent significantly less time in the novel chamber than Ss undergoing long-term or short-term social isolation. The handling variable was found to interact significantly with postweaning rearing and test days. (PsycINFO Database Record (c) 2010 APA, all rights reserved)