Scientists have long known that the experiences you have in infancy and childhood play an important role in shaping how your brain develops and how you behave as an adult. But figuring out why this is happening has been difficult.
For the past 15 years, my team and I have studied the development of children’s brains to determine which aspects of early life experiences influence brain maturation. In our recently published paper, summarizing our findings from numerous animal and human studies, we found that unpredictable or inconsistent parental behavior can disrupt the development of a child’s emotional circuitry. This can lead to an increased risk of mental illness and substance abuse later in a child’s life.
Predictability and Consistency
To solve the problem of figuring out which signals influence the development of the brain’s emotional systems, we took clues from how the brain’s sensory systems, such as vision and hearing, develop. Environmental cues are important for sensory development. For example, if an infant is unable to see adequately due to a strong lazy eye, they may develop vision deficits for life. Similarly, an infant who cannot distinguish patterns and sequences of everyday sounds due to frequent ear infections may develop hearing problems for life.
Since parents are often the main source of information that an infant and young child receives from the environment, we thought it would be reasonable to assume that parental cues are critical to brain development. Previous studies over decades have shown that the behavior of caregivers and how responsive they are to their child’s needs were important to the child’s emotional growth. Lack of response, for example due to neglect, has been associated with an increased risk of emotional problems later in life.
While many studies have focused on the impact of “positive” or “negative” parental behavior on a child’s brain development, researchers have paid little attention to behavioral patterns or parental predictability and consistency. A predictable and consistent parent is one who reacts in the same way to new situations, such as when their child falls easily or asks for a new toy. In the long run, predictability also means that the child knows who will pick him up from school and when he can expect lunch, dinner or bedtime.
We first conducted our studies in mice and rats in order to be able to control the behavior of mothers towards their young, limiting the amount of material available in the environment for building nests, changing the patterns of their activity towards offspring. We then conducted human studies looking at how mothers behave during structured play sessions and how their behavioral patterns affect the emotional and cognitive development of their children.
To quantify maternal behavior in these sessions, we measured the extent to which one behavior predicted the next. For example, the likelihood that a mother would talk to a child and show him a toy was a good indicator of how often she would pick up the child. We also took into account other aspects of upbringing and environment, such as socioeconomic status. We assessed the development of children and puppies using cognitive and emotional tests, as well as behavioral questionnaires for children.
In all of our animal and human studies, we have found that predictable parenting patterns lead to better emotional and cognitive functioning in their children later in life. Although our research has focused primarily on mothers, it is highly likely that the same principles apply to fathers.
Supporting Your Child’s Brain Growth
Our results show that not only “positive” or “negative” parenting affects the development of the child. Equally important to the emotional development of a child’s brain is that parents raise them in a predictable and consistent way.
There are many hardships beyond the parents’ control that can affect their child’s development, such as poverty, war, and migration. However, understanding the role that predictable and consistent behavior plays in brain development can help parents create an optimal environment for their child as they grow emotionally.