New study links low incomes, stressed parents and child behaviour – better support would bring lifelong benefits

Poverty has long been established as a crucial factor hindering the development of young children. Living in poverty can hurt a child’s lifelong health, social and educational outcomes.

But much less is known about the way income affects children via its effect on their parents.

In Aotearoa New Zealand, 12.5% of children live in material hardship, which means their households are going without some of the essentials due to cost.

Our new study examined whether a higher family income helps support children’s behavioural development. This is important, as children’s behavioural (or social and emotional) development sets the foundation for longer term positive mental health and academic success.

Our findings highlight the importance of supporting parents to be engaged with preschool children. And one of the key ways to do this is to reduce poverty and parental stress.

Income and behaviour

To better understand the links between childhood poverty and behaviour, we used data from more than 6,000 New Zealand mothers and their children in the Growing Up in New Zealand study. We followed the children from pregnancy to eight years of age.

We examined the same families over time and then broke down what was causing the differences in behavioural development between children from high and low-income families.

In particular, we looked at children’s social and emotional development by examining a combined score which reflected their conduct, hyperactivity, emotion and peer relationship problems, as reported by their mothers.

Children with high scores may have problems with areas such as friendship and paying attention at school, and these issues may be a forerunner for future mental health problems.

Our results showed that for periods where family income was higher, children had fewer reported behaviour problems than during periods where income was lower – but only in the preschool years.

A higher family income seemed to help children’s early social and emotional development and head off behaviour problems. But why?

The role of adults

During the preschool years, back and forth (known as “serve and return”) interactions between adults and children are considered crucial for children’s brain development.

And in our models, the factors driving differences in preschool behavioural development scores are those related to the mother-child relationship.

Some of the most important factors were differences in mothers’ stress, and in parenting behaviours related to stress, such as yelling and arguing with children.

While facing small challenges in a supportive environment is good for children’s development, being constantly exposed to a stressful environment during these developing years has been shown to wire children’s brains in unhealthy ways.

Mothers on lower incomes had higher levels of stress. When we examined what was driving these differences in stress across the income groups, we found maternal health and housing issues, such as moving frequently, were driving factors.

Overall, a higher income appears to lower stress and create space for more engaged parenting, benefiting children’s social and emotional development.

How does technology fit?

We also saw important differences in children’s screen time and reading together with parents.

When we compared children against themselves at different points in time, greater screen use was associated with more behaviour problems at two and four-and-a-half years, but not at eight years.

Screen use also explained some of the differences in behavioural problems across the income groups – but it was part of a wider picture and should not be considered in isolation.

But it is about balance. In Aotearoa, parents are often without day-to-day practical support (such as extended family) to help with caregiving. Technology may be the only way some parents feel they can get a break.

Investing in parents to help children

While our results give clear support for increasing income to encourage children’s social and emotional development, this doesn’t necessarily mean encouraging all mothers back to work. Working mothers also had higher levels of stress.

Our findings do suggest any policies that increase parental wellbeing are likely to have flow-on benefits for young children. Conversely, any policies that increase stress for parents are likely to negatively affect children’s development.

This means government agencies that support families should make it as easy as possible for families to access that support, and ensure it is provided consistently and with certainty