The reduction in personal responsibility felt by each individual in a group, leading to inaction because each person assumes someone else will act.
From Latin 'diffusio' (a pouring forth) + 'responsabilis' (answerable). Responsibility spreading thin across a group.
Diffusion of responsibility is 'not my problem' multiplied by a crowd — when everyone thinks someone else will help, nobody does. That's why the bystander effect happens.
Complete word intelligence in one call. Free tier — 50 lookups/day.