Principal and Derivative Comparisons
This chapter suggests that young organisms of many species come armed with programs of behavioral development that, in their own way, are as "canalized" as those for the development of a limb or a heart. Ethological studies of the stimulus control of behavior have a "Gibsonian" bias, as in use of the complex stimuli that emanate from inanimate models of members of the species in postures of display. In embryological development the relative timing of events is crucial in determining the final product of processes of growth. The same is true of behavioral development, because different situations will be encountered at different stages of the life cycle. The relative stereotypy of the basic coordinations of action that underlie the natural patterns of animal behavior was epitomized in a concept from classical ethology that could only have been derived from comparative research, that of the "fixed action pattern".