• Hu, M.,& Kirkegaard, E. O. W.(2026). Left-wing ideology, mental health and body modifications. Journal of Open Inquiry in the Behavioral Sciences, 5(1).

Recent research has identified a recurring association between left-wing political ideology and poorer mental health. These findings show both reduced positive well-being (e.g., life satisfaction) and increased negative symptoms (e.g., depression, anxiety). We administered 76 mental health and 41 political ideology items to a sample of 978 fairly representative American adults recruited via the Prolific data platform. Overall, we found that every aspect of mental health correlated negatively with overall leftism (r’s for 18 diagnoses = -0.20, last 2 weeks symptoms = -0.14, MMPI-subset = -0.17, life satisfaction = -0.15, all p’s < .001). Diagnoses were the primary predictor of leftism in multivariate models. This relationship was not explained by measurement bias, as invariance testing revealed only minimal, counter-balancing item bias. Furthermore, we expanded this network by incorporating behavioral markers, finding that body modifications (e.g., unnatural hair color, tattoos) showed weak-to-modest associations with both left-wing ideology and mental health diagnoses.

The purpose of the study was mainly to check the measurement invariance of the relationship, since many people had doubted this. Perhaps leftists are just more likely to see therapy or maybe they fill out questionnaires differently. For this reason, we went a bit overboard with the mental health measurement having 76 questions, 18 concerning specific diagnoses and the remaining the more commonly used self-report questions about various aspects. Politics was measured using 41 questions concerning various current thing political questions for Americans, and scored just using the 1-factor model. (Yes, one can extract other dimensions but this one is dominant.) General results:

The various scales called “p” are mental health reversed (worse) based on different approaches. Symptoms is all the self-report scales items combined, diag = diagnoses count, MMPI = items from MMPI (yes/no format), last2weeks (typical format used in surveys), satisfaction (positively phrased questions about life satisfaction). The rightmost column shows that leftism correlates positively with every variable except for age. Given these demographic associations (age, female), one may want to try a regression model to see if leftism correlates with mental problems merely because it is correlated with age and femaleness:

The answer is no, not only, but maybe in part. Diagnoses correlates 0.20 with leftism but 0.16 controlled for age, sex, US-born, and race (though the CI overlaps with 0.20). More interesting is that the models that include both self-report measures and diagnoses counts, the diagnoses have the signal and the others turn non-significant (but stay positive). With ~1000 people, we can’t say whether diagnoses count mediates the entire effect but possibly. One could even try controlling for self-reported mental problems and see if leftism still predicts diagnoses:

Continues….