A team of international experts studied sleep-inducing techniques used by parents in 14 different cultures and discovered a correlation between them and a child's temperament development.

To encourage optimal behavioural development across cultures, the researchers advised putting more emphasis on better sleep-related parenting techniques.

The importance of good sleep during childhood development has been extensively researched. Bad sleep quality and behaviors are detrimental to neurobehavioral functioning, emotional reactivity, and regulation, and can pose a risk for future psychopathology.

"Parental sleeping techniques are correlated with children's sleep quality, and the importance of cultural context in child development has been long recognised," said corresponding author Ms Christie Pham, of Washington State University.

"We wanted to examine whether cross-cultural differences in parental sleep-supporting strategies account for differences in toddler temperament," she added.

In a study published in Frontiers in Psychology, Pham and her colleagues studied the effect of different parental sleep-supporting techniques on child temperament across 14 cultures.

They hypothesised that passive ways of helping a child fall asleep (eg, cuddling, singing, and reading), but not active methods (eg, walking, car rides, and playing), would be positively related to a child's temperament.

Child temperament

Child temperament is defined as the way children regulate their behavior and handle their emotions. Different child temperaments can have an effect on his/her mental and physical well-being and can pose a risk for future disorders.

Researchers previously defined temperament by three overarching factors -- Surgency (SUR), which reflects positive affect such as smiling and laughter, approach tendencies, activity, and enthusiasm; Negative Emotionality (NE), which captures overall distress proneness, including in situations eliciting fear, anger, sadness, and discomfort and Effortful Control (EC), involving attention-based regulatory skills and enjoyment of calm activities.

Each of the factors independently contributes to predicting behavioral, achievement, and interpersonal outcomes, such as behavior problems, social competence, and academic performance.

The international group of researchers asked 841 caregivers across 14 cultures (Belgium, Brazil, Chile, China, Finland, Italy, Mexico, Netherlands, Romania, Russia, Spain, South Korea, Turkey, and the US) to fill in the early childhood behavior questionnaire and a daily activities questionnaire.

They were asked to report on their toddler's (between 17 and 40 months of age, 52% male) temperament and their sleep-supporting parenting techniques, respectively.

"Utilising linear multilevel regression models and group-mean centering procedures, we assessed the role of between- and within-cultural variance in sleep-supporting practices in relation to temperament," said Pham.

Active vs passive sleep support

They found that differences in sleep-supporting methods between cultures and within the same culture were associated with different temperament characteristics. The difference was larger between cultures, meaning that sleeping methods independently contribute to differences in child temperament across cultures.

"Our study shows that a parent's sleep-supporting techniques are substantially associated with their child's temperament traits across cultures, potentially impacting their development," said Pham.

"For example, countries with greater reliance on passive strategies had toddlers with higher sociability scores (higher SUR)," Pham continued. On the other hand, fussy or difficult temperament (higher NE) was significantly correlated with active sleep techniques.

Overall, passive sleep-supporting techniques were associated with lower NE and higher SUR at the culture level and higher EC at the individual level. Active sleep-supporting techniques were associated with higher NE at an individual level only.

Rank-ordering the extent to which a culture's sample endorsed using passive techniques, the results show that the US, Finland, and the Netherlands top the list, and South Korea, Turkey, and China are at the bottom of this distribution.

In contrast, in rank-ordering for active techniques, the researchers find that Romania, Spain, and Chile top the list while Turkey, Italy, and Belgium are at the bottom of the distribution.

"Our results demonstrate the importance of sleep promotion and suggest that parental sleep practices could be potential targets for interventions to mitigate the risk posed by challenging temperament profiles across cultures," said Pham.