An excellent summary, but I have a question. Could not the endogenous personality solve problems affecting their own life (or immediate family's), and so affect their own reproduction chances, instead of merely doing things that affect the group's survival chances? If so, could it be a consequence not just of group selection but also individual selection?
@ajb - The idea is that the Endogenous personality is rather like a diversion of attention and effort away from the social/ sexual and to other matters. In a 'social animal' such as the humans, *on average* this diversion of effort, attention etc. would almost-inevitably reduce the chances of reproductive success. It is also hard to see how this individual reduced RS could or would be compensated by a sufficient enhancement of genetic relatives (inclusive fitness). If something arises that tends significantly to reduce reproductive success, then it should not evolve by individual selection. The usual alternative would assume that the Endogenous personality was therefore an accident, not an adaptation. (i.e. that people with the Endogenous personality were a pathology - a fitness-reducing state, not an adaptation.) Or group selection - which would be that the behaviour evolves because the benefit to reproductive success goes to the group, rather than to the individual. This is actually not so rare an idea about evolutionary theorists as you might imagine; but the difficulty is that there is not any one standard understandable mechanism by which group selection might happen.However, there need not be a single mechanism, and anyway it seems likely that group selection may be a special case of the 'integrative' mechanism required to sustain life, and to increase the complexity of life - given the tendency of lower level individual selection to subvert and destroy higher level complexity (e.g. in cancer). http://charltonteaching.blogspot.co.uk/2014/09/reconceptualizing-natural-selection-as.htmlIn sum, I don't think biologists are required to make group selection a 'diagnosis of exclusion', i.e. there is not a requirement to eliminate every possibility of individual level selection before group selection is allowed to be possible. It seems, on the contrary, that group selection (in its general sense of higher level selection) is something which is, indeed *must be*, going-on all over the place and absolutely fundamentally, for life to originate, to be maintained, and to increase in complexity.
The endogenous personality seems to be an extreme form of the introvert or perhaps a better word is introspect.I have some personal experience as an introspect, and I must say I never tire of the creative ways in which my mind examines and plays with emotions and thoughts. One of my great joys is that creative thinking and ecstasy seem to be very closely connected in my introspective mind. I think that one of the surest signs of it is when a man or woman prefers the company of his own thoughts to the din of social noise. It is not that I cannot appreciate others, but the things people prattle on about in social settings are by and large so much mental flotsam and jetsam. If I am at a party and I can quietly exit to go for a walk or sit by a river or in a garden, oh that is so much better. And if someone joins me, and we sit and preferably say very little but only take in the serenity of silence, then I am very happy indeed. My thoughts are free to wander where they may, and playfully explore whatever small thing reminds me of how wondrous it is to live and breathe and think and feel all these things that are life. So yes, I understand what it is to be an introspect, but being one does not mean closing myself off, but being tuned to a different voice - one that sings in brooks, leaves, birdsong, stars and reflections of moonlight over a near still lake at night. Beauty is my muse, and awe is my companion. Others of my kind can sit with me or climb a mountain ridge with me, but the society I long for is one in which we are content to experience something communally without disturbing each other with prattle.