Investigating the effects of age and autonomous locomotion on infant location use during the first year

This study investigated the influence of age and autonomous locomotion on infants’ use of physical spaces during the first year of life. A total of 18 healthy infants (8 male, 10 female) were observed longitudinally in their homes from an average starting age of 2.77 months through 12 months. Monthly, naturalistic video recordings captured approximately 30 min of uninterrupted spontaneous play per infant, with the researcher acting as a passive observer. Continuous coding quantified the frequency and duration of infants’ use of distinct locations (e.g., floor, crib, caregiver). Results revealed that infants experienced comparable affordances across households, validating true behavioral variation rather than differential access. Location frequency did not vary with age, but crawling infants visited more locations than pre-crawlers. Time in restrictive locations decreased with age, while floor time increased, particularly before crawling onset. Ultimately, developmental changes were characterized by reduced time in restrictive locations and greater time on the floor, with total frequency of explorations more closely tied to locomotor status than chronological age.