Over and over again the research on cooperation says: human beings are highly cooperative. But we don't believe it. WHY? This massive global study (over 100k participants from 125 countries!) finds we are highly cooperative *and* that we underestimate others' cooperation. The likely reason is because as a species we survive with cooperation but the costs of potentially being betrayed are so high that we are over-vigilant about the possibility. This can be MOVED https://www.science.org/doi/10.1126/science.aec9483