Attempts to link the Big Five personality traits of Openness-to-Experience, Conscientiousness, Extraversion, Agreeableness, and Neuroticism with variability in trait-like features of brain structure have produced inconsistent results. Small sample sizes and heterogeneous methodology have been suspected in driving these inconsistencies. Here, using data collected from 1,107 university students (636 women, mean age 19.69 ± 1.24 years), representing the largest sample to date of unrelated individuals, we tested for associations between the Big Five personality traits and measures of cortical thickness and surface area, subcortical volume, and white matter microstructural integrity. In addition to replication analyses based on a prior study, we conducted exploratory whole-brain analyses. Four supplementary analyses were also conducted to examine 1) possible associations with lower-order facets of personality; 2) modulatory effects of sex; 3) effect of controlling for non-target personality traits; and 4) parcellation scheme effects. Our analyses failed to identify significant associations between the Big Five personality traits and brain morphometry, except for a weak association between greater surface area of the superior temporal gyrus and lower conscientiousness scores. As the latter association is not supported by previous studies, it should be treated with caution. Our supplementary analyses mirrored these predominantly null findings, suggesting they were not substantively biased by our analytic choices. Collectively, these results indicate that if there are associations between the Big Five personality traits and brain structure, they are likely of very small effect size and will require very large samples for reliable detection.

中文翻译：

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几乎没有证据表明大五人格特征与大脑灰质或白质变异之间存在关联


尝试将开放性、责任心、外向性、宜人性和神经质这五大人格特征与大脑结构的类似特征特征的变异性联系起来，但产生了不一致的结果。小样本量和异构方法被怀疑是造成这些不一致的原因。在这里，我们使用从 1,107 名大学生（636 名女性，平均年龄 19.69 ± 1.24 岁）收集的数据（代表迄今为止无关个体的最大样本），测试了大五人格特征与皮质厚度和表面积测量值之间的关联，皮质下体积和白质微观结构完整性。除了基于先前研究的重复分析之外，我们还进行了探索性全脑分析。还进行了四项补充分析来检查：1）与人格低阶方面的可能关联； 2）性的调节作用； 3）非目标人格特质的控制效果； 4) 分割方案的影响。我们的分析未能确定大五人格特征与大脑形态测量之间的显着关联，除了颞上回较大表面积与较低责任心得分之间的微弱关联之外。由于后者的关联没有得到先前研究的支持，因此应谨慎对待。我们的补充分析反映了这些主要无效的发现，表明我们的分析选择并未对它们产生实质性偏见。总的来说，这些结果表明，如果大五人格特征与大脑结构之间存在关联，那么它们的效应大小可能非常小，并且需要非常大的样本才能进行可靠的检测。