Genetic Influences on Hormonal Markers of Chronic HPA Function in Human Hair

Abstract

Cortisol is the primary output of the hypothalamic-pituitary-adrenal (HPA) axis and is central to the human biological stress response, with wide-ranging effects on physiological function and psychiatric health. In both humans and animals, cortisol is frequently studied as a biomarker for exposure to environmental stress. Relatively little attention has been paid to the possible role of genetic variation in heterogeneity in chronic cortisol, in spite of well-studied biological pathways of glucocorticoid function. Using recently developed technology, hair samples can now be used to measure accumulation of cortisol over several months. In contrast to more conventional salivary measures, hair cortisol is not influenced by diurnal variation or transient hormonal reactivity. In an ethnically and socioeconomically diverse sample of 1 070 child and adolescent twins and multiples from 556 unique families, we estimated genetic and environmental influences on hair concentrations of cortisol and its inactive metabolite, cortisone. We identified sizable genetic influences on cortisol that decrease with age, concomitant with genetic influences on cortisone that increase with age. Shared environmental influences on cortisol and cortisone were modest and, for cortisol, decreased with age. Twin-specific, non-shared environmental contributions to cortisol and cortisone became increasingly correlated with age. We find some evidence for sex differences in the biometric contributions to cortisol, but no strong evidence for main or moderating effects of family socioeconomic status on cortisol or cortisone. This study constitutes the first genetic study of hormone concentrations in human hair, and provides the most definitive characterization to-date of age and socioeconomic influences on hair cortisol. Genetics of Chronic HPA Function

Brilliance Beliefs, Not Mindsets, Explain Inverse Gender Gaps in Psychology and Philosophy

“…Based on theory and some evidence (e.g., e.g., Halvorson, 2011;Dweck, 2007), we expect that women will hold more fixed versus growth mindsets than men. Given that other evidence suggests no gender difference (e.g., Tucker-Drob et al, 2016;V. Yan et al, 2014) or a difference in the opposite direction (e.g., Macnamara & Rupani, 2017), this hypothesis is tentative.…”

“…Notwithstanding work on the benefits of growth versus fixed mindset, there is a notable lack of empirical evidence to support the "Bright Girl" theory-that women, especially those relatively high in intelligence, are more likely to have fixed (vs. growth) mindsets relative to men, and that these fixed mindsets make these "bright girls" especially likely to opt out of challenging tasks (e.g., Halvorson, 2011;Dweck, 2007). Instead, findings related to gender differences in mindsets are mixed: Some work has found no gender differences in mindsets (e.g., Tucker-Drob et al, 2016;V. Yan et al, 2014); whereas other work finds that gender differences in mindsets depend on culture (e.g., with women, compared to men, holding more growth mindsets in a Western sample, but more fixed mindsets in an Eastern sample; Z.…”

Associations Between Polygenic Scores for Cognitive and Non-cognitive Factors of Educational Attainment and Measures of Behavior, Psychopathology, and Neuroimaging in the Adolescent Brain Cognitive Development Study

“…This limits study generalizability, which may be especially important for better understanding potential relationships between facets of academic achievement and factors related to health and well being. Second, the outcome measures studied were constrained by what was available in the ABCD Study, and therefore do not include all potential measures of interest (e.g., personality traits that are considered to be important to non-cognitive aspects of educational attainment and success; Humphries & Kosse, 2017;Malanchini et al, 2023;Tucker-Drob et al, 2016;von Stumm et al, 2011). Relatedly, we were unable to assess all of the same imaging modalities that prior papers have reported on, including mode of anisotropy.…”

“…Despite often being thought of as a purely "environmental" factor, EduA itself is moderately heritable (h 2 =0.41-0.47; Heath et al, 1985;Silventoinen et al, 2020), and the genetic contributions to EduA can be broken down into component traits. Evidence that EduA is strongly impacted by cognitive ability and a set of broadly defined "non-cognitive skills" (e.g., emotion regulation and personality traits such as grit and curiosity; Chamorro-Premuzic & Furnham, 2003;Duckworth et al, 2007Duckworth et al, , 2019Kovas et al, 2015;Malanchini et al, 2019;Noftle & Robins, 2007) has inspired recent approaches that have deconstructed the genetic architecture of EduA into cognitive and non-cognitive components that have shared and unique associations with EduA-related phenotypes (e.g., risk-taking and psychopathology; Malanchini et al, 2023;Tucker-Drob et al, 2016;Tucker-Drob & Harden, 2012). The extent to which these differential associations extend to childhood, before education has been completed, remains poorly understood (Malanchini et al, 2023).…”

Self-control and grit are associated with school performance mainly because of shared genetic effects

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