Instead of overthinking and assume that people don't want to upset social hierarchy, I suggest the researchers to take a step back and consider that people prefer symbiotic over the antibiotic scenario. In this "game", we may not know how A came to wealth, but we would be certain how A lost wealth. Similarly in the second scenario, while we know B is still less wealthy compared to A, at least B is wealthier than before. Value creation vs Value transfer. (Entrepreneur v. Investment Banker)