Exploring Dopamine Genotype as a Moderator of the Effect of Parental Behavior on Children’s Self-Control

• February 03, 2022
• Daphne Vrantsidis, PhD

Did you know developmental psychologists have found the secret to life success?

It’s not eating your vegetables or doing your homework or anything else your parents or teachers told you growing up.

It’s how long you waited to eat a marshmallow when you were 4 years old.

Delaying gratification — waiting 5 minutes to eat two marshmallows instead of eating one immediately — is part of larger construct called self-control. Self-control is the ability to carry out goal-directed behavior in rewarding or emotionally arousing situations.

By preschool, self-control is an important predictor of the development of psychopathology, including behavior problems like ADHD; health outcomes, like obesity; and psychosocial functioning, like adjustment, across the lifespan.

Because of the importance of early self-control across the lifespan, it is important to identify, at an early age, which children are at risk for poorer self-control and modifiable environmental factors important for the development of self-control.

Factors Associated with Self-Control: Parent Behavior and Dopamine

Two specific dimensions of parental behavior linked to children’s self-control are responsiveness and harsh discipline. Responsiveness refers to a parent’s warmth and contingent responses to children’s behavior and how well these responses match children’s behavior. Responsiveness is associated with better self-control in early childhood. Harsh discipline includes coercive or inconsistent parental behavior, or the use of harsh punishment to manage children’s behavior. Harsh disciple is associated with poorer self-control in early childhood.

In addition, dopamine is involved in motivational, reward, and attention processes. Low dopamine availability is associated with poorer self-control. Genetic risk for low dopamine availability may moderate the effect of parental behavior on children’s self-control, in particular parental behavior may have a greater impact on children’s self-control in children at higher genetic risk for low dopamine availability.

How Do These Factors Affect Children’s Self Control?

Does genetic risk for low dopamine availability moderate the effect of responsiveness and harsh discipline on children’s self-control? This is the question I set out to answer with my study, which was published in Development and Psychopathology in November 2021. To do so, we studied pairs of mothers and children.

Mothers and their 36-month-old children were videotaped interacting during four tasks: cleaning up, completing challenging puzzles, waiting while mothers were busy, and free play. The videotapes of these tasks were then coded for maternal responsiveness and harsh discipline.

Next, we collected and genotyped children’s saliva samples. DNA for four dopamine genes was extracted:

• COMT or catechol-o-methyltransferase involved in the degradation of dopamine
• DAT1 or dopamine transporter 1 involved in the release of dopamine into the synapse
• DRD2 and DRD4 – dopamine receptors D2 and D4 – involved in the uptake of dopamine from the synapse

The number of variants of these genes associated with low dopamine availability was used as the measure of dopamine genetic risk.

Finally, children completed two self-control tasks.

First, children stood in front of chocolate candies for 5 minutes and were told they could not eat them.

Second, children sat in front of a shelf full of toys for 15 minutes and were told they could not play with them.

In terms of differences in the association between maternal behavior and children’s self-control by children’s dopamine genotype, I found support for an interaction between dopamine genotype and harsh discipline but not dopamine genotype and responsiveness. Further, there was no main effect of responsiveness on children’s self-control.

When I examined the form of the interaction between dopamine genotype and harsh discipline on children’s self-control, I found the following: mothers’ use of harsh discipline was associated with poorer self-control for children at higher genetic risk for reduced dopamine availability relative to children at low genetic risk for low dopamine availability.

What Are the Implications of This Study?

My results provide a proof of concept for a measure of dopamine genotype as a biological marker indicating which children may potentially be at risk for poor self-control. This is particularly exciting because genes are present from birth —meaning we can identify children who are potentially at-risk for poorer self-control at an early age and intervene in early childhood to improve self-control in these children, a critical period for self-control development.

The results also suggest that parental behavior, particularly harsh discipline, is one modifiable environmental factor linked to children’s self-control. Thus, interventions, such as those aimed at helping parents use more positive discipline strategies, such as limit setting, rather than harsh discipline may be one effective method at improving self-control, particularly in at-risk children.

Finally, results suggest that we may be able to target interventions to children most likely to be at-risk for poorer self-control or most likely to benefit from the intervention, such as targeting parenting interventions to children at high genetic risk for poorer self-control. This is particularly important as resources for interventions are limited, and targeted interventions would help tailor interventions to children most likely to benefit from them.

Reference:

Vrantsidis DM, Clark CAC, Volk A, Wakschlag LS, Espy KA, Wiebe SA. Exploring the interplay of dopaminergic genotype and parental behavior in relation to executive function in early childhood. Development and Psychopathology. 2021 Nov 15. [Epub ahead of print]

About the author

Daphne Vrantsidis, PhD

Dr. Vrantsidis is a developmental psychologist and postdoctoral scientist in the Center for Biobehavioral Health at the Abigail Wexner Research Institute at Nationwide Children’s Hospital. Dr. Vrantsidis’ research focuses on how parental behavior impacts the development of self-regulation in children at risk for behavior problems.

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