Children’s facial expressions following a lack of sleep may predict future social issues, according to new research.

A team from University of Houston investigated whether restricting sleep for children could have a knock-on effect on their emotional functioning and cause longer-term social issues.

Candice Alfano, professor of psychology at University of Houston, said: “Sleep problems in children are routinely linked with lower social competence and more problems in peer relationships, but we really don’t understand what drives these associations.”

The new study follows on from previous research by Professor Alfano, and she set out to test whether children’s facial expressions when fatigued could be behind these associations.

The study involved 37 children between the ages of seven and 11 who participated in two emotional assessments. One assessment consisted of well-rested children, and the other consisted of children who had been partially sleep deprived for the previous two nights.

A selection of images was shown to the children, some designed to evoke positive emotions and others designed evoke negative emotions. At the same time, a high-definition camera recorded and documented their facial expressions. Their parents then provided the researchers with accounts of their children’s behaviour at the time of the assessment, and then again around two years later.

Professor Alfano explained: “As we suspected, children who displayed less positive facial expressions in response to pleasant images when sleep restricted were reported to have more social problems two years later, even when controlling for earlier social problems.”

Researcher Alfano argued that, although concurrent links were not observed between the change in facial expressions due to restricted sleep and social issues, this could be due to developmental variances in the children’s social performance and peer relations.

Professor Alfano said: “For younger children, more explicit behaviours such as sharing and taking turns may be more important for friendships than subtle facial expressions. However, emotional expression becomes more important with age.”

She continued: “Facial expressions not only provide others with an understanding of how you are feeling but are known to have a contagion effect on how others feel.”

The results back up the growing body of research which suggest a lack of sleep in children anticipates future socio-emotional problems and highlights the significance of research into how sleep impacts children’s mental wellbeing. Lack of sleep has been proven to negatively affect the way children display emotions through their facial expressions, a vital part of social interaction.

The findings have been published in Affective Science.

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