on Approach Tendency in Ch icks

Earlier research has shown that brief amounts of social stimulation prior to testing results in an increased tendency in chicks to approach and follow a novel object. Those studies could not, however, distinguish between the effects of viewing animate objects and the effects of simple activation due to disturbances in the subjects ' rearing situations. The current study manipulated the effects of environmental novelty and exposure to objects independently. It was found that exposure to a novel environment prior to testing produced evidence for activation. Exposure to objects during pro-nounced changes in the rearing condition reduced latency to approach a novel object in a later test, but exposure to a novel environment without exposure to objects, or exposure to objects under conditions of low environmental novelty, did not produce such a reduction. There is ample evidence that chicks tend to approach familiar animals or objects. Socially reared chicks make reliable social discriminations between broodmates of familiar and unfamiliar color (Rajecki and Lake, 1972; Salzen and Cornell, 1968) and between broodmates and animals of another species (Pattie, 1936). Preference for the familiar also obtains when chicks are imprinted on artificial targets and then tested for discriminative social choices between original and new targets (Guiton, 1959; Sluckin and Taylor, 1964; Smith and Hoyes, 1961). Conversely, chicks that have been reared socially for prolonged periods appear to be inhibited in responding positively to the exclusive presentation of a novel target. Salzen (1962) reports that chicks reared in isolation for 24 hr were more likely to show pleasure ("contentment " calls, approach, and/or nestling behavior) on the initial presentation of an artificial target.(64 % of the group) than were chicks that had been reared socially for the same perio