Infants’ sense of self revisited: Mixed evidence from two studies on 6-month-olds’ preference for delayed visual feedback

It has been reported that infants prefer to look at delayed feedback of their leg movements compared to real-time feedback of their leg movements. In Study 1, 6-month-old infants participated in this delay task and their leg activity was monitored during the task. The infants did not prefer the delayed video image to the real-time video image. There was no robust relation between infants’ leg activity and time spent looking at the delayed video image. In Study 2, we tested the reliability of a preference for the delayed video image at the group level and individual level. Another group of 6-month-old infants were tested twice on the same delay task. Although the infants as a group preferred the delayed video image to the real-time video image at both time points, there was no intra-individual stability of this preference. These results provide mixed evidence for the reliability of a delay preference at the group level and no evidence for a delay preference at the individual level. This finding is a call to action for other areas of developmental psychology to be more cautious about assumptions of intra-individual stability in task performance.