it’s contagious!

the interest in inbreeding/outbreeding and altruism, that is!

henry harpending contemplates inbreeding/outbreeding and the dark side of altruism: “ethnic or racial discrimination and enmity.”

cool! (^_^) thnx to chris for pointing the post out to me!

(note: comments do not require an email. henry harpending.)


  1. The example of Japanese moving to France made me think more that if there’s a postively and negatively reinforced altruism then the negative (threat-based) one at least may be best looked at as a threesome rather than a twosome i.e. it’s an elastic i or us compared to two (or more) thems.

    – i, my brother, my cousin
    – our extended family, extended family on the other side of the valley, extended family from outside the valley
    – wessex people, kent people, vikings
    – wessex people, vikings, martians

    up and down along the scale working backwards in terms of least different rather than most similar.


  2. @g.w. – what prof. harpending said over on west hunter:

    “For example if you are inbred your kinship with yourself is greater than 0.5 but your relationship to yourself is still unity. It seems that the appropriate transform is that the relationship of person a to person b is the kinship between a and b divided by the kinship of a with himself. This means the relationship of a to b is not in general the same as the relationship of b to a.”


    the first sentence there is what i tried to illustrate with mr. blue square (’cause i can’t really do the math either! — i think in pictures). when person a/mr. blue square is inbred, his kinship with himself is greater than if he weren’t inbred because he’s inherited duplicate copies of some alleles from each parent (identical by descent). so in my visualization, person a/mr. blue square shrinks in size — in prof. harpending’s algebra, person a/mr. blue’s kinship with himself increases in number.

    the last sentence is also evident in my little squares. b/mr. blue square’s father has given half of his dna to his son, a/mr. blue square. but a/mr. blue square has, in fact, inherited even more of his father’s genes from his mother since his mother and father were cousins. so, a/mr. blue square is even more related to his father than his father is to him.

    does that make any sense?

    i can’t help you with sentence number two — that one just zipped over my head so quickly my hair was fluttering in the breeze. (~_^)


  3. @g.w. – “up and down along the scale working backwards in terms of least different rather than most similar.”

    yes, absolutely!

    i’ve been (half-heartedly) trying to figure out how to put this because sometimes if you start talking about altruistic behavior with people and how kin-selection means you ought to favor your family more than outsiders, someone will invariably point out that siblings fight all the time, or whatever. but it really is all a matter of context (and how many resources are available, etc., etc.). sure, brothers will go at it because they don’t share 100% of their dna (unless they’re identical twins — and even then there are differences). but toss in a hated cousin and suddenly the brothers are allies. (^_^)


  4. “does that make any sense?”

    “but it really is all a matter of context…brothers will go at it…but toss in a hated cousin and suddenly the brothers are allies. (^_^)”

    Yes to both. it’s what i call the pullme-pushyou for want of an even remotely explainable alternative. I can half-picture it but looking at it as a backwards threesome (fnar fnar) feels like a step in the right direction.


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