Groups that find themselves in the same area become kin a few generations later.
So I don't see why kin selection must be the sole mechanism to explain all kinds of group selection. The group dominates the individual by indoctrination from a young age, as well as by force. You can refer to all this as "culture". The group is smart enough to threaten the individual with things that the individual cares about, and the individual has evolved to be receptive to such correction by the group, and learn to stop doing something, even if it would give them a better reproductive fitness.
It just so happens that groups which live together start becoming genetically related down the line. But the mechanism that acts isn't kin selection.
So I don't see why kin selection must be the sole mechanism to explain all kinds of group selection. The group dominates the individual by indoctrination from a young age, as well as by force. You can refer to all this as "culture". The group is smart enough to threaten the individual with things that the individual cares about, and the individual has evolved to be receptive to such correction by the group, and learn to stop doing something, even if it would give them a better reproductive fitness.
It just so happens that groups which live together start becoming genetically related down the line. But the mechanism that acts isn't kin selection.