An innate period of familial preferences in chicks not imprinted

Abstract

White Leghorn chicks hatched and reared in visual isolation were tested for innate preferences in a choice situation of age-mate paired against a hen. Thirty-two Ss were tested at each of the following ages: 1, 12, 24, 36, 48, 60, 72, and 84 h since hatching. The mean response of the younger Ss was to the hen, but the preference for age-mate increased steadily until a maximum was reached at 36 h of age post-hatch, when it began to decline, approaching zero preference at 84 h.