Preference on cash-choice task predicts externalizing outcomes in 17-year-olds

Area of Science:

• Behavioral economics
• Behavioral genetics
• Adolescent psychology

Background:

• Delay-discounting, the preference for smaller-sooner over larger-later rewards, is a key indicator of impulsivity.
• Impulsivity and externalizing behaviors are frequently associated, with a heritable genetic component.
• Adolescence presents heightened risk for externalizing behaviors, necessitating valid assessment tools.

Purpose of the Study:

• To validate the "cash-choice" delay-discounting measure in older adolescents.
• To investigate the genetic and environmental influences on delay-discounting and externalizing behaviors in twins.
• To determine if cash-choice can serve as an endophenotype for externalizing behaviors.

Main Methods:

• Utilized a sample of 791 17-year-old twins from the Minnesota Twin Family Enrichment study.
• Administered a "cash-choice" task to assess delay-discounting preferences.
• Applied biometric modeling (univariate and bivariate) to analyze genetic and environmental influences.

Main Results:

• Individuals preferring smaller-sooner rewards reported higher substance use, earlier sexual activity, and lower GPAs.
• Univariate models confirmed heritability for both cash-choice behavior and externalizing tendencies.
• Bivariate modeling indicated that the link between cash-choice and externalizing behaviors is primarily driven by shared environmental factors, not genetics.

Conclusions:

• The "cash-choice" task is a valid measure of individual differences in decision-making for older adolescents.
• Delay-discounting, as measured by cash-choice, does not appear to be a genetic endophenotype for externalizing behaviors in this age group.
• Shared environmental influences, rather than genetic factors, largely explain the association between delay-discounting and externalizing behaviors by late adolescence.