> I’m arguing that free individuals in those societies with the power to choose otherwise, and access to information about the consequences of their choices, don’t get to blame those norms for their behaviour.
Fair enough, but I care less about how to apportion moral blame for society's collective failings, and more about how to fix it, into a society able to sustain itself and produce exceptional children.
Plenty of people in society act contrary to the norms. In fact modern developed societies are incredibly diverse relative to the way they were a few generations ago in terms of lifestyle choices. Individual people do have agency, do have the power to choose and many of them exercise it.
Do again it comes down to responsibility. Averages are a measurement of outcome, not a determinant of it for individuals in the sample.