Functional versus other types of imprinting and sensitive periods in Gallus chicks

Literature on “imprinting,” a process whereby social preferences are presumably “stamped in” as a result of exposure during a very brief sensitive or critical period, is voluminous, yet much of it may have little relationship to social attachment processes. Domestic chicks remain responsive to biologically appropriate stimuli for several days posthatching and do not exhibit behavior which suggests that they learn to prefer to socialize with objects to which they have earlier been trained regardless of when they were exposed. Social attachment processes are of huge evolutionary and ontogenetic significance; imprinting, as it is usually defined and measured, may not reflect social attachment.