Is Progressive Ideology on the Test? Education and Intelligence in the Development of Nontraditional Attitudes.

Enhanced educational attainment and intelligence are consistent correlates of socially liberal, nontraditional attitudes. However, it is unclear how such associations unfold developmentally. Here, we propose an interaction effect between college exposure and intelligence on the development of nontraditional attitudes.

Limited psychological and social effects of lifetime cannabis use frequency: Evidence from a 30-year community study of 4,078 twins.

Background: Cannabis use is associated with outcomes like income, legal problems, and psychopathology. This finding rests largely on correlational research designs, which rely at best on statistical controls for confounding. Here, we control for unmeasured confounders using a longitudinal study of twins.

Recreational cannabis legalization has had limited effects on a wide range of adult psychiatric and psychosocial outcomes.

Background: The causal impacts of recreational cannabis legalization are not well understood due to the number of potential confounds. We sought to quantify possible causal effects of recreational cannabis legalization on substance use, substance use disorder, and psychosocial functioning, and whether vulnerable individuals are more susceptible to the effects of cannabis legalization than others.

Methods: We used a longitudinal, co-twin control design in 4043 twins ( = 240 pairs discordant on residence), first assessed in adolescence and now age 24-49, currently residing in states with different cannabis policies (40% resided in a recreationally legal state).

Impacts of recreational cannabis legalization on cannabis use: a longitudinal discordant twin study.

Aims: To estimate the effect of recreational legalization on cannabis use frequency and sources of variance across legal environments.

Design: Longitudinal discordant twin and gene-environment interaction models in twins recruited from birth records and assessed prospectively.

Setting: The United States, including states with different recreational cannabis policies before and after 2014, when recreational cannabis was first legalized.

The clashing nature of rebelliousness: Nontraditional attitudes and counter-normative behaviors show divergent associations with intelligence.

Objective: Prior literature indicates that nontraditional attitudes are linked to higher intelligence. However, such attitudes in adolescence often accompany counter-normative, delinquent-type behaviors, which are themselves negatively linked with intelligence. This points to the possibility of suppression in the relationship between intelligence and nontraditional attitudes.