Table 1.
Summary of studies included in the systematic review and meta-analysis
| Trait | # Studies | Sample (median, range) | Female/Male | Mean Age (range) |
|---|---|---|---|---|
| Meta-Analysis Gray Matter Volume | ||||
| Neuroticism | 17 | 3340 (87, 37–1104) | 1878/1462 | 33.75 (17–85) |
| Extraversion | 18 | 3099 (68, 30–1104) | 1726/1373 | 33.4 (17–85) |
| Agreeableness | 12 | 2760 (97.5, 37–1104) | 1562/1198 | 36.32 (17–85) |
| Conscientiousness | 12 | 3148 (132, 37–1104) | 1750/1398 | 35.43 (17–85) |
| Openness | 11 | 2784 (116, 37–1104) | 1583/1201 | 37.74 (17–85) |
| Systematic Review Gray Matter Volume | ||||
| Neuroticism | 51 | 15 563 (102.5, 19–1870) | 8613/6826 | 33.81 (12–90) |
| Extraversion | 47 | 11 928 (87, 19–1870) | 6520/5284 | 34.43 (12–88) |
| Agreeableness | 32 | 10 769 (112, 19–1870) | 5781/4615 | 32.6 (12–85) |
| Conscientiousness | 34 | 11 136 (113, 19–1870) | 6140/4872 | 35.08 (12–88) |
| Openness | 32 | 10 686 (125.5, 19–1870) | 5886/4676 | 33.14 (12–85) |
| Systematic Review Cortical Thickness | ||||
| Neuroticism | 19 | 7944 (223, 14–1106) | 4485/3459 | 36.25 (14–85) |
| Extraversion | 12 | 4048 (165.5, 14–1104) | 2359/1689 | 37.74 (14–85) |
| Agreeableness | 11 | 5016 (265, 28–1104) | 2889/2127 | 36.93 (14–85) |
| Conscientiousness | 11 | 5016 (265, 28–1104) | 2889/2127 | 36.93 (14–85) |
| Openness | 11 | 4184 (223, 28–1104) | 2427/1757 | 36.31 (14–85) |
| Systematic Review Surface Area | ||||
| Neuroticism | 8 | 4825 (542.5, 56–1106) | 2676/2149 | 38.27 (17–85) |
| Extraversion | 7 | 3719 (507, 56–1104) | 2076/1643 | 38.27 (17–85) |
| Agreeableness | 7 | 3719 (507, 56–1104) | 2076/1643 | 38.27 (17–85) |
| Conscientiousness | 7 | 3719 (507, 56–1104) | 2076/1643 | 38.27 (17–85) |
| Openness | 8 | 3904 (386, 56–1104) | 2170/1734 | 36.24 (16–85) |
Note. Among the systematic review studies, some studies (Joffe et al., 2009; Nair et al., 2016; Yang, Hou, et al., 2017) did not report the demographic information for the final sample; this was the case when, for example, only some participants contributed personality trait and/or structural image data, but a study only reported the demographic information for the total sample.