Constitutional biases in early perceptual learning: I. Preferences between colors, patterns, and composite stimuli of colors and patterns in genetically manipulated and imprinted quail chicks (C. coturnix japonica).

Bidirectional genetic selection of quail for early color preferences, for eighteen generations, resulted in nearly perfect choices of blue over red in one and red over blue in the other selected line. It also enhanced the preference of a grated over a dotted black-and-white pattern. Color and pattern preferences in hybrids of selected and control lines fell back to about halfway between parental values. Choices between composite stimuli of colors and patterns indicated summation of the respective, genetically influenced preference values, with partial dominance of color over pattern effects. Exposure to colors modified color choices. Exposure to colored patterns likewise modified color choices, but it did not change, or only marginally changed, choices between patterns. The phenotypic expression of this selective learning, however, was influenced by the genetically manipulated preference values and preference combinations of colors and patterns in the stimuli with which postexposure performances were tested. Overall, the data highlighted the need for concepts that would discriminate between the developmental and the episodic expression of genetic influences and genotype--environment interactions in behavior.