Abstract

It is known that, by 9-12 months of age, infants' discrimination abilities tune into the species, race, gender and age of faces with which the most experience has been accumulated, as part of a domain-general developmental process, known as perceptual narrowing, occurring at the same time across different perceptual domains, including face processing. As for age, the extensive amount of social and perceptual experience accumulated with caregivers and/or other adult individuals induces the tun ing of discrimination abilities towards adult faces. The aim of the current study was to test natural experience acquired with an older sibling's face is capable to modulate perceptual narrowing towards adult faces in 9-month-old infants. To this aim, we tested discrimination abilities for adult and child faces in 9-month-old infants with and without an older sibling. Results showed that infants with sibling succeeded in discriminating child faces but infants without sibling failed to do so even in the presence of a maintained ability to discriminate among adult faces. These findings replicate earlier demonstration of perceptual narrowing towards adult faces in 9-month-old infants, and provide the first evidence that natural experience acquired in everyday context with the sibling's face can modulate this process.