Genetic and environmental influences on impulsivity: A meta-analysis of twin, family and adoption studies

Abstract

A meta-analysis of twin, family and adoption studies was conducted to estimate the magnitude of genetic and environmental influences on impulsivity. The best fitting model for 41 key studies (58 independent samples from 14 month old infants to adults; N = 27,147) included equal proportions of variance due to genetic (0.50) and non-shared environmental (0.50) influences, with genetic effects being both additive (0.38) and non-additive (0.12). Shared environmental effects were unimportant in explaining individual differences in impulsivity. Age, sex, and study design (twin vs. adoption) were all significant moderators of the magnitude of genetic and environmental influences on impulsivity. The relative contribution of genetic effects (broad sense heritability) and unique environmental effects were also found to be important throughout development from childhood to adulthood. Total genetic effects were found to be important for all ages, but appeared to be strongest in children. Analyses also demonstrated that genetic effects appeared to be stronger in males than in females. Method of assessment (laboratory tasks vs. questionnaires), however, was not a significant moderator of the genetic and environmental influences on impulsivity. These results provide a structured synthesis of existing behavior genetic studies on impulsivity by providing a clearer understanding of the relative genetic and environmental contributions in impulsive traits through various stages of development.

The evolution of self-control

“…For example, animals require self-control when avoiding feeding or mating in view of a higher-ranking individual, sharing food with kin, or searching for food in a new area rather than a previously rewarding foraging site. In humans, self-control has been linked to health, economic, social, and academic achievement, and is known to be heritable (170)(171)(172). In song sparrows, a study using one of the tasks reported here found a correlation between self-control and song repertoire size, a predictor of fitness in this species (173).…”

Genetic influences on dietary variety - Results from a twin study

“…4 To the degree that food variety seeking is a specific aspect of a more general trait comprising the need for external stimulation or sensory-specific satiety, one might expect similarities between the degree of variety that people seek across different domains beyond food (Inman, 2001). Thus, a promising route for further exploration would be to test for relationships between food variety seeking, variety seeking in other domains, differences in satiety levels, the general desires to explore and seek novelty, and other related phenotypes, including "supertaster" ability (Bezdjian, Baker, & Tuvblad, 2011;Duffy & Bartoshuk, 2000;Helm & Landschulze, 2009;Pessemier & Handelsman, 1984). Along the same lines, the current analysis should be extended by using more refined measures of food variety seeking that not only go beyond the item level but also take relevant attributes, including nutrient content or texture, into account.…”

Chevauchement entre les trajectoires de jeu et les trajectoires de consommation de psychotropes au début de l’adolescence : une étude longitudinale génétiquement informative

“…Ces endophénotypes, qui servent de média-teurs entre les gènes et les trajectoires de SUP ou de JHA, peuvent prendre la forme de comportements impulsifs. Ces comportements sont effectivement des prédicteurs établis de consommation de SUP et de participation à des JHA et ils comportent une composante génétique importante (Bezdjian et al, 2011). Le troisième objectif visait précisément à regarder si les endophénotypes associés aux différentes trajectoires sont les mêmes et s'ils sont modérés de la même manière par les facteurs de l'environnement.…”

“…Par exemple, l'impulsivité est un facteur de risque reconnu en regard de la consommation de SUP et de la participation à des JHA. En conséquence, ce facteur de risque, lui-même hautement « héritable » (Bezdjian, Baker, & Tuvblad, 2011) devrait, selon un principe de « dosage effet », distinguer les adolescents cheminant sur des trajectoires élevées de JHA et de SUP de ceux qui cheminent sur une trajectoire élevée de JHA ou de SUP.…”