"Personality tests don't predict job performance." I hear this dismissal frequently. And it's wrong. Meta-analyses consistently show conscientiousness predicts performance across virtually all jobs (ρ = .22-.27). Emotional stability follows close behind. That might seem modest until you realise: → It holds across industries, roles, and cultures → It's incremental validity beyond cognitive ability → Combined with ability tests, prediction jumps to .50+ The issue isn't whether