Procrastination, a tendency to postpone one’s actions, would be associated with a genetic predisposition involving a higher level of dopamine in the brain. A correlation demonstrated by a study in women and that is not found in men.
Is there a male-female inequality on the subject of procrastination, this tendency to postpone actions that can be carried out in the moment? Nothing demonstrates this in fact and yet a study published in the journal Social Cognitive and Affective Neuroscience of July 3 shows that this attitude is, in some women, linked to a genetic predisposition to a higher level of dopamine in the brain. The authors of this study were unable to identify the same correlation in men.
The crucial role of dopamine
Whether a person tends to postpone tasks or tackle them directly depends on their ability to maintain a specific intention to act without being distracted by disruptive factors. It is in this mechanism that dopamine could play a crucial role. This neurotransmitter is not only associated with increased cognitive flexibility, but also appears to facilitate the entry of information into working memory.
The research group studied the genotype of 278 men and women and was particularly interested in the tyrosine hydroxylase gene (TH gene). Depending on the expression of this gene, people’s brains contain different amounts of neurotransmitters from the catecholamine family, the family to which the neurotransmitter dopamine belongs. From responses to a questionnaire to record how well participants were able to control their actions, it appeared that women with lower ability to control had a genetic predisposition to higher levels of dopamine.
“More distracted by environmental factors”
“We hypothesize that this high level of dopamine which increases cognitive flexibility makes it more difficult to maintain a distinct intention to act. Women with a higher level of dopamine due to their genotype would therefore tend to delay actions because they are more distracted by environmental factors”, explains the doctoral candidate Caroline Schlüter who participated in this study.
Differences between males and females in TH gene expression
Why does such a mechanism not appear in the men studied by the research group? Previous studies have revealed differences between males and females in the effects of TH gene expression on behavior. “Estrogen, a female sex hormone, seems to play a role,” says Erhan Genc, another author of the study, recalling that estrogen directly influences the production of dopamine in the brain. “Women might therefore be more susceptible to genetic differences in dopamine levels due to estrogen, which, in turn, is reflected in behavior.”
In future studies, the research team will investigate to what extent estrogen levels actually influence the relationship between the TH gene and action control. “This would require looking more closely at the menstrual cycle and the associated fluctuations in participants’ estrogen levels,” says Caroline Schlüter.
