Niche diversity effects on personality measurement – evidence from large national samples during the COVID-19 pandemic

•Personality structure systematically varies across 16 large population samples.•Niche diversity and wealth effects show credible effects on personality structure.•Acute population-level threats due to COVID-19 do not show credible effects.•Life expectancy showed the most consistent results, suggesting new avenues for improving theorizing about niche effects on personality structure.