||Adults communicate with infants using modified action. Infants prefer these infant-directed (ID) modifications compared to adult-directed action (ADA). This study is a step toward clarifying what specific feature of infant-directed action (IDA) sustains infant attention the most. Range of motion was manipulated so that 6- to 8-month old infants viewed two displays of similar action, side-by-side, varying only in their range of motion. Infant preference was measured and in line with our hypothesis, infants showed a significant preference for actions with a larger range of motion, although only in the second set of trials. Possible reasons for differences across trials are explored in the discussion. In sum, this work suggests that a larger range of motion sustains infant attention and may offer learning benefits as well.