Cross-sectional and longitudinal observations of pointing gestures by infants and their caregivers in Japan

•Caregivers produced index-finger pointing more frequently than did younger infants.•Older infants' frequency of index-finger pointing was similar to caregivers'.•Infants whose caregivers produced pointing soon after that of their infants produced index-finger pointing more frequently 7 months later.

In two studies, I investigated the impacts of caregivers' pointing gestures on the developmental increase in the frequency of infants' index-finger pointing. In Study 1, I replicated Liszkowski et al., (2012) study, wherein infants and caregivers engaged in 5-min interactions in a decorated room. In Study 2, younger infants and their caregivers who participated in Study 1 were observed about 7 months later in a similar decorated room as in Study 1. Both studies showed that caregivers produced index-finger pointing more frequently than did younger infants, whereas older infants' index-finger pointing was comparable to caregivers'. Study 2 demonstrated that caregivers' contingent pointing-namely, index-finger pointing less than 6 s after young infants' pointing-led to an increase in infants' frequency of index-finger pointing 7 months later. These results suggested that caregivers' contingent pointing has the function of promoting active production of index-finger pointing by infants.