Measuring the tides of talk

Behavioural science has capitalised on the ubiquitousness of smartphones to collect real-time naturalistic data from adults, shedding light on how long they sleep, for example, or how their moods change over time. Gathering similar data from young children is more challenging because they are not attached to mobile phones like most of us adults, and they don’t have the necessary language skills to accurately report on their own experiences.

Of course, we can ask parents to provide extensive details about their child’s environment, but this is quite a cognitive burden even for the most attentive parent. Which raises this question: How can we gather accurate, valid naturalistic data on the environments of young children from their own perspective?

“How can we gather accurate, valid naturalistic data on the environments of young children from their own perspective?”

A possible answer comes in the form of a little purple box equipped with a tiny microphone and digital language processor. This equipment compresses audio files so that recording can continue for up to 16 hours without the need for recharging or downloading the data. I invited families with a child between the ages of 2 and 3 to test whether these audio recorders might serve as a kind of smartphone for data collection purposes.

The 107 children were given clothes such as dungarees and dresses that were specifically designed to include pockets in the front so that the audio recorders could be “worn” by the children without encumbering their daily activities. After 3 full days of audio recordings, the parents and children completed a test booklet designed to assess the children’s non-verbal cognitive abilities, such as reasoning and problem solving.

Overall, aside from the fact that one of the recorders ended up in the washing machine and a few children were adamant that they would only wear certain colours – who knew preschoolers could be such fashionistas? – the study was successful in demonstrating that these little purple boxes could give us unprecedented insight into the children’s lives and acoustic environments.

“I found a positive association between the number of words spoken by adults and the children’s cognitive abilities.”

I found a positive association between the number of words spoken by adults and the children’s cognitive abilities. While my study design is unable to show whether hearing more adult talk actually leads to better performance on a test of cognitive ability, it raises the question of the mechanism that underpins this association. It may be that more intelligent children have better social skills and thus elicit more talk from adults in their environments, or perhaps more adult talk coincides with greater exposure to ideas and learning opportunities.

Surprisingly, I also found that children heard vastly different amounts of adult talk from one day to the next. We had assumed that some families were just more talkative than others, but it appears that there are massive fluctuations in the amount of talk a family engages in from day to day and from hour to hour. Some children heard twice as many words one day as they did the next.

This suggests that children’s language environments are more like the tides of the ocean than the stillness of a lake. Developmental research that values naturalistic observations of substantial time periods is likely to increase our understanding of the complex interplay between children and their changing environments.

“Children’s language environments are more like the tides of the ocean than the stillness of a lake.”