Infant Attachment and Toddlers’ Sleep Assessed by Maternal
Reports and Actigraphy: Different Measurement Methods Yield
Valerie Simard,1 PHD, Annie Bernier,2 PHD, Marie-Eve Belanger,2 BSC, and Julie Carrier,2,3 PHD
Received June 5, 2012; revisions received January 7, 2013; accepted January 9, 2013
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.