Infant Attachment and Toddlers’ Sleep Assessed by Maternal Reports and Actigraphy: Different Measurement Methods Yield Different Relations

OBJECTIVE: To investigate relations between children's attachment and sleep, using objective and subjective sleep measures. Secondarily, to identify the most accurate actigraphy algorithm for toddlers. METHODS: 55 mother-child dyads took part in the Strange Situation Procedure (18 months) to assess attachment. At 2 years, children wore an Actiwatch for a 72-hr period, and their mothers completed a sleep diary. RESULTS: The high sensitivity (80) and smoothed actigraphy algorithms provided the most plausible sleep data. Maternal diaries yielded longer estimated sleep duration and shorter wake duration at night and showed poor agreement with actigraphy. More resistant attachment behavior was not associated with actigraphy-assessed sleep, but was associated with longer nocturnal wake duration as estimated by mothers, and with a reduced actigraphy-diary discrepancy. CONCLUSIONS: Mothers of children with resistant attachment are more aware of their child's nocturnal awakenings. Researchers and clinicians should select the best sleep measurement method for their specific needs.