Because in this model, kindness to kin evolved because we share a significant fraction of our genes with our close kin (1/2 for children, siblings, and parents; 1⁄4 for grandchildren, grandparents, uncles/aunts/nieces/nephews; etc.). If there’s instead an ant queen, then all ants in this particular colony are siblings, but genetic relatedness to other hives is very low. Then you don’t get kindness to kin but something else, like kindness to hive or self-sacrifice for hive.
EDIT: I think the above holds, but the justification in EY’s Twitter thread is different, namely that “Human bands and tribes are the right size for us to need to trade favors with people we’re not related to” but scaled-up ant colonies are not.
Because in this model, kindness to kin evolved because we share a significant fraction of our genes with our close kin (1/2 for children, siblings, and parents; 1⁄4 for grandchildren, grandparents, uncles/aunts/nieces/nephews; etc.). If there’s instead an ant queen, then all ants in this particular colony are siblings, but genetic relatedness to other hives is very low. Then you don’t get kindness to kin but something else, like kindness to hive or self-sacrifice for hive.
EDIT: I think the above holds, but the justification in EY’s Twitter thread is different, namely that “Human bands and tribes are the right size for us to need to trade favors with people we’re not related to” but scaled-up ant colonies are not.