Delinquent Peer Group Formation: Evidence of a Gene × Environment Correlation

Q&A flashcards covering the key concepts, methods, results, and interpretations from the study on gene–environment correlation (rGE) in delinquent peer formation.

What is a gene × environment correlation (rGE)?

The idea that genetic factors influence the environments people select or evoke, including passive, evocative, and active forms.

Which gene and allele did the study focus on in relation to delinquent peer affiliation?

The dopamine transporter gene DAT1, specifically the 10-repeat allele (10R).

From which data source did the authors analyze genotypic data?

The National Longitudinal Study of Adolescent Health (Add Health).

What was the analytical sample size with genotype data?

N = 1,816 individuals.

In which subgroup did DAT1 predict delinquent peers?

Male adolescents from high-risk environments (high family risk).

Was DAT1 associated with delinquent peers in the full sample or among females?

No significant association in the full sample or among female adolescents.

How was delinquent peers measured in Wave 1?

Three-item scale: number of closest friends who smoke daily, drink monthly, or smoke pot monthly; the sum is standardized.

What are the three main types of rGE?

Passive, Evocative, and Active gene-environment correlations.

What is homophily in the context of this article?

Tendency to associate with others who are similar in traits, characteristics, or behaviors.

How were DAT1 alleles coded for analysis?

Alleles were recoded as 0, 1, or 2 copies of the 10R allele.

What were the allele frequency distributions for DAT1 in the sample?

0 copies: 5.3%; 1 copy: 35.1%; 2 copies: 59.6% of the 10R alleles.

What family-risk measures were used?

A composite measure from maternal attachment, maternal involvement, and maternal disengagement, dichotomized into low vs high risk.

What did Table 3 test for, and what was found?

Tests for spuriousness by adding delinquency, low self-control, and drug/alcohol use; DAT1 remained associated with delinquent peers in high-risk male adolescents.

How did the DAT1 effect interact with family risk?

Significant for high-risk male adolescents across models; not significant for low-risk males.

What is the main conclusion of the study?

There is an rGE between DAT1 and delinquent peer affiliation, especially among high-risk male adolescents, suggesting genetics partly influence selection into delinquent peer networks.