AbstractIncubating chicks were presented with a high‐intensity or low‐intensity photic flicker stimulus, or with no photic stimulation. The chicks were tested at 16 hr posthatching for approach behavior, or at 96 hr for imprinting performance to the 2 visual flicker stimuli. The data were analyzed in accord with the arguments of whether those stimuli that effectively elicit approach behavior are determined by interaction between maturation and experience or by a genetic program. The results show that prehatch exposure to photic flicker stimuli affects initial approach behavior and imprinting performance, supporting the interaction position in opposition to the genetically programmed posit