‘IU study finds infant attention span suffers when parents’ eyes wander during playtime – Eye-tracking study first to suggest connection between caregiver focus and key cognitive development indicator in infants’, http://news.indiana.edu/releases/iu/2016/04/infant-attention-span.shtml, Indiana University (April 28, 2016).

Social influences

Caregivers who seem distracted or whose eyes wander a lot while their children play appear to negatively impact infants’ burgeoning attention spans during a key stage of development. (…) Historically, psychologists regarded attention as an property of individual development. (…) Social influences on attention are potentially very important and ignored by most scientists.