The Left is more intelligent (I need evidence backing my claim)
Executive summary
Recent, peer-reviewed and media-covered research finds a measurable correlation between higher cognitive ability and left/liberal political attitudes: a 2024 family-based study using measured IQ and polygenic scores reports intelligence predicts social liberalism and lower authoritarianism within families [1] [2] [3]. Prior meta-analyses and reviews show a long history of similar findings but also important caveats: effects vary by type of ideology (social vs economic), measurement, and potential confounding by environment and education [4] [5] [6].
1. The strongest new evidence: within-family genetic and IQ analyses
A University of Minnesota team published in Intelligence and summarized across outlets that measured IQ and polygenic scores for cognitive performance and educational attainment both predicted left-leaning social attitudes and lower authoritarianism even when analyzed within biological and adoptive families — which the authors argue strengthens causal inference that intelligence influences political beliefs [1] [2] [3]. Popular coverage echoed the headline that genetic indicators and IQ correlated with left-wing views, while acknowledging methodological complexities [7] [8].
2. What “left” and “intelligence” mean in these studies
The reported associations are not blanket statements that “the Left is more intelligent” in every sense; the literature distinguishes social liberalism (e.g., lower authoritarianism, favoring social liberties) from economic conservatism/liberalism, and finds intelligence relates more strongly to some dimensions (social liberalism) than others (economic views) [1] [6] [5]. Studies also use different intelligence measures (IQ tests, nonverbal tasks, polygenic scores) and political measures (party ID, social attitudes, authoritarianism), which affects results [4] [6].
3. Historical research and meta-analytic context
Meta-analyses and earlier large studies have generally found negative correlations between cognitive ability and conservative attitudes—many studies reported lower cognitive ability associated with higher right‑wing authoritarianism—though some findings differ by country, measure, and time period [4] [6]. Reviews note inconsistency: some economic attitudes show different patterns, and theoretical accounts debate whether intelligence causes ideology or both reflect shared environmental or genetic factors [4] [5].
4. Causality, genetics, and environmental confounds
The 2024 family-based study claims stronger causal inference because within-family designs control for many shared environmental factors, and polygenic scores add a genetic angle; yet the authors and commentators emphasize alternative interpretations remain plausible — educational attainment, socioeconomic environment, and other non‑cognitive traits captured by polygenic scores could mediate or confound the association [1] [2]. Science reporting noted the findings are “provocative” but fraught with the usual nature–nurture complexities [7] [8].
5. What the evidence does not support (and what sources don’t say)
Available sources do not support a sweeping, value-laden claim that one political side is categorically “more intelligent” in all contexts, nor do they claim intelligence explains every political difference; instead, current reporting and reviews show nuanced, dimension‑specific associations and methodological caveats [1] [4] [5]. If you ask whether all left‑wing people are smarter than all right‑wing people, the sources do not make that universal claim [5].
6. Competing interpretations and agendas to watch for
Some scholars interpret the correlation as intelligence causally shaping openness and lower authoritarianism; others emphasize measurement choices, time-period shifts, or that polygenic scores for education capture non-intelligence traits — each interpretation can reflect implicit agendas (e.g., genetic determinism vs. social-environmental explanations) and influences how results are publicized [1] [6]. Media pieces amplified bold headlines while also noting complexity, which can feed polarized public readings [7] [8].
7. How to use these findings responsibly
If citing this literature, distinguish types of ideology (social vs economic), name the measures used (IQ, PGS, authoritarianism), and state limitations: within-family and genetic indicators strengthen inference but do not fully settle causality or rule out socioeconomic mediation [1] [2] [4]. Avoid overgeneralizing from correlations to moral judgments about political groups — the peer-reviewed work frames effects as probabilistic and partial, not determinative [1] [3].
Sources cited: University of Minnesota family study and related entries on the Intelligence paper and its ScienceDirect/PubMed records [1] [2] [3], media summaries and commentary (Futurism, Dazed) [7] [8], and prior reviews/meta-analytic context [4] [5] [6].