Locomotion and nightwaking

Objective: In this study we addressed the association between two major achievements of infancy: independent locomotion and 'sleeping through the night'. Methods: Mothers of 107 healthy infants aged between five and eight months completed a sleep questionnaire and a motor checklist. Results and conclusions: Infants who were already crawling had more bedtime difficulties and nightwaking than did pre-crawlers. Among 7- and 8-month-old infants, locomotion predicted 17% of nightwaking variance, after controlling for age and gender. In discussing the developmental implications of locomotion we suggest that crawling may not only 'broaden the mind' but also 'cost' sleep. More studies, across time, on how motor development and sleep-wake regulation interrelate are recommended.