You could say the same thing about your drinking water or the food you buy. Modern society is complex, and even simpler historical societies were dependent on

You could say the same thing about your drinking water or the food you buy. Modern society is complex, and even simpler historical societies were dependent on cooperation before we got anywhere near the level of complexity and specialization we deal with today. At the end of the day it’s a trust issue. Studies, be they medical, scientific, or observational, are one way to build trust. There are many others, but I’m not sure how well they scale with the size of a society compared to the systems we have in place today.