We talk about personality as if it were permanent. You are introverted. You are ambitious. You are bad with people. The language is solid, almost geological, as though personality were something discovered rather than formed.

Introversion feels ancient. We imagine quiet observers in every era, standing slightly apart from the crowd. But the way we understand introversion today as a stable personality type, even an identity may be far more modern than it appears.

Violence is often measured by what can be counted: wars fought, bodies buried, crime rates logged. By those metrics, humanity appears to be improving. Fewer interstate wars, declining homicide rates in many regions, longer stretches of relative peace. On paper, it looks like progress. But violence has never been limited to what leaves visible wounds.