Infants' looking preferences for social versus non-social objects reflect genetic variation

Area of Science:

• Developmental Psychology
• Behavioral Genetics
• Cognitive Neuroscience

Background:

• Individual differences in infant attention to social stimuli are crucial for development.
• Understanding the interplay of genetic and environmental factors in early attention is key.
• Previous research has not fully elucidated the heritability of face preference in infants.

Purpose of the Study:

• To determine the extent to which genetic and environmental factors influence infants' preference for faces over objects.
• To investigate the heritability of early face orienting and sustained face preference.
• To explore the association between infant face preference and later verbal competence.

Main Methods:

• Utilized a sample of 536 5-month-old same-sex twins.
• Employed eye-tracking technology to measure initial orienting to faces and sustained face preference.
• Applied twin model fitting to estimate genetic, shared, and unique environmental influences.

Main Results:

• Heritability estimates for face orienting and face preference were 0.19 and 0.46, respectively.
• Genetic and unique environmental effects influenced face orienting and preference, with no shared environmental effect.
• Sustained face preference was positively associated with later parent-reported verbal competence (β=0.14).

Conclusions:

• Individual differences in infants' preference for social (faces) versus non-social (objects) stimuli are heritable.
• Findings highlight the role of genetic factors in early perceptual input selection.
• This study offers a developmental perspective on gene-environment interplay evident in infant eye movements and social attention.