Mothers, strangers or morphs? Infants facial preferences revealed

Infants prefer the face of their mother, or that of a stranger, to a computer generated face morphing the two. This ‘uncanny valley’ between familiarity and novelty was discovered in a Japanese study and is published in Biology Letters.

Children were shown a computer generated face composed 50% of their mother’s face and 50% of a stranger’s. When presented with this morphed image alongside an image of either their mother or a stranger, the children were found to look longer at, and thus prefer, the familiar and novel faces (those of mother and stranger, respectively) over the morphed face. This effect strengthened with the infant’s age.

Yoshi-Taka Matsuda and his team at the Japan Science and Technology Agency found that both the difference in looking time between mothers’ faces and intermediate faces, and between strangers and intermediate faces was significant; with less than a 1 in 1000 chance of the result being down to chance. However, no significant difference was found between mothers and strangers. These results show that infants have a lower preference for intermediate faces.

The ‘uncanny valley’ response is a phenomenon involving the elicitation of a negative feeling and subsequent avoidant behaviour in human adults and infants as a result of viewing very realistic human-like robots or computer avatars. It is hypothesized that this uncanny feeling occurs because the realistic synthetic characters elicit the concept of ‘human’ but fail to satisfy it. Such violations of our normal expectations regarding social signals generate a feeling of unease. The result of the study in Biology Letters indicates that an “uncanny valley” between familiarity and novelty may accentuate our perception of familiar and novel objects.