SPECIES IDENTIFICATION AND COLOUR PREFERENCES IN CHICKS

Naive chicks, whether of a yellow (Vantress) or black variety (sex-link), show no consistent tendency to approach other chicks of the same variety. When communally housed in the light with chicks of their own variety they do develop a preference for chicks of their own kind. However, when housed with chicks of the alien variety, no consistent preferences appear. Socially housed Vantress chicks do not discriminate 'own-kind' on the basis of colour. If housed with Vantress chicks dyed a dark blue, they then show a preference for a similarly dyed Vantress chick. This result still obtains when the test is performed with immobile and silent dummies, indicating that under these conditions, some attribute of 'blue' is perceived. Preferences for own-kind are immanent, but require activation by a particular experience. Programming of perceptual systems such that an experience is prerequisite to a response, but with only certain kinds of experiences or responses being possible, seems to be an important feature of organisms. © 1968.