Kometani Atsushi, Ohtsubo Yohsuke
Department of Psychology, Graduate School of Humanities, Kobe University, Kobe, Japan.
Department of Social Psychology, Graduate School of Humanities and Sociology, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
Evol Hum Sci. 2022 May 24;4:e21. doi: 10.1017/ehs.2022.22. eCollection 2022.
Previous studies have suggested that human impulsivity is an adaptive response to childhood environmental harshness: individuals from families of low socioeconomic status (SES) tend to be more impulsive. However, no studies have tested the evolvability of this reaction norm. This study examined whether (a) impulsivity is associated with higher fitness among individuals from low SES families, while (b) it is associated with lower fitness among individuals from high SES families. We assessed three indices of impulsivity (temporal discounting, risk taking and fast/slow life history strategy), childhood SES and five proxy indices of fitness (number of children, lifelong singlehood, annual household income, subjective SES and life satisfaction) of 692 middle-aged participants (40-45 years old). None of the results supported the evolvability of the impulsivity reaction norm, although low childhood SES was associated with lower fitness on every proxy measure. Impulsivity (operationalised as the fast life history strategy) was associated with lower fitness regardless of childhood SES.
以往的研究表明，人类的冲动性是对童年时期环境严苛程度的一种适应性反应：来自社会经济地位（SES）较低家庭的个体往往更冲动。然而，尚无研究检验这种反应规范的可进化性。本研究考察了：（a）冲动性是否与来自低SES家庭的个体具有更高的适应性相关，而（b）它是否与来自高SES家庭的个体具有较低的适应性相关。我们评估了692名中年参与者（40 - 45岁）的三个冲动性指标（时间贴现、冒险行为和快/慢生活史策略）、童年SES以及五个适应性代理指标（子女数量、终身单身、家庭年收入、主观SES和生活满意度）。尽管童年SES较低在每项代理指标上都与较低的适应性相关，但没有结果支持冲动性反应规范的可进化性。无论童年SES如何，冲动性（以快生活史策略来衡量）都与较低的适应性相关。
