乳児における女性顔選好性の検討

抄録

A previous study (Quinn and others, 2002) has indicated that infants reared by a mother preferred female faces to male faces. This preference would be made through the infants' experiences of faces. In order to test any cultural differences, the present study investigated the preferences of Japanese infants for female faces. In Experiment 1, each infant was presented with two faces in six preference trials of 10 seconds duration. The two stimuli were randomly selected from three facial stimuli: an average female, an average male, and an androgyne. The results revealed that the infants did not prefer a feminine face. In Experiment 2 distinctive faces were made using a morphing system to create new face stimuli: a '125% hypermale', a '125% hyperfemale', a '75% hypermale' and a '75% hyperfemale'. Each infant was presented with each pair of the four stimuli in four preference trials of 20 seconds duration. The results revealed that infants of 5-6 months preferred the feminine face in the female face condition, but infants of 3-4 and 7-8 months did not have any preference. In addition, to investigate the influence of contrast sensitivity we used inverted face stimuli. A preference for any inverted face was not displayed by any infant. These results suggest that infants of 5-6 months are capable of discriminating female faces.