Milestones or Millstones: How Standard Assessments Mask Cultural Variation and Misinform Policies Aimed at Early Childhood Development

Traditionally, the study of motor development—rooted in Western populations and culture—has focused on establishing norms in the timing and sequence of motor skills, inspiring the widely used emphasis on motor milestones in standard assessments (e.g., crawling by 8 months). Motor milestones are only a perceived version of what is an important skill; they are cultural conventions, not universals. Some cultures allow infants floor time; others carry them constantly, limiting practice. Thus, milestones create millstones to considerations of culture and context. Cultural beliefs, practices, and expectations manifest in childrearing practices. The variability in childrearing—or differences in infants’ experiences—offer unique opportunities for posture, balance, and locomotion, which in turn generates variation in motor skills both within and between cultures. Cross-cultural comparisons best illustrate the enormous variability in infants’ everyday experiences and effects on motor skills. We offer suggestions from this cross-cultural perspective to inform policy when designing interventions to help infants and young children thrive.