Every now and then a group secedes from general society and goes its own way. Sometimes they end up living a very different kind of life. Less often, that different way of life persists.
I’m thinking of the Puritans, the Quakers, the Amish, the Oneida Community, the Nation of Islam, California communes, and of course the Harshmanites.
Do those different ways of life influence intelligence? According to the sociologists they could, and maybe should. According to the psychometricians and behavioral geneticists, they could if they had differential recruitment [ immediate results] , or if they were reproductive isolated and had different internal selective pressures [ slow ].
Has there been such a change caused by the new social environment? In other words, could such a subsociety just decide to be smarter?