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Hello and welcome back
in this module we're going to be inquiring into how the ways we interact with our relatives might be the product of natural selection.
I hope you enjoy it let me know if you have any questions
Hello I'm Kendall House and this presentation is called William D Hamilton's social universe
Hamilton has been called...
he's right at the foundation of the evolutionary study
of animal and human behavior
and he recently passed away.
So when we look at contemporary neo- Darwinian social theory including the book you're reading
Meeting at Grand Central - there's just a tremendous flood of publications on cooperation and altruism
and Hamilton is a source of that flood.
So we're gonna go back to Hamilton's first paper in 1963 where he mapped out a social universe
and later he published papers on all four corners of this social universe.
In his first paper
it was based on the result of the action of one agent on another
so it's just a two agent model
one agent acts on the other
and there's an outcome to that
and in Hamilton's universe there's four possible outcomes. So we're gonna call these agents Blue and Orange.
and alternatively I'll refer to them as A and B
that it's a little shorter to say.
So what's the first outcome? Well, the first outcome is Blue harms Orange
and as a result Blue benefits.
So we're gonna symbolize harm by red and benefit by green, so now we've turned Blue green, and we turn
Orange red.
and what Blue's done is benefited by harming another.
Or at the expense of another. And this defines the selfish corner of Hamilton's universe.
And we represent that with a plus and the arrow to the minus, so the gain
to the negative.
There's three more corners, but this is
kind of the originating one, and we could call this ordinary Darwinism.
This is what Huxley and others popularized in Darwin's thinking
fitness gains to the victor
fitness losses to the loser
We tend to think of this in very dramatic terms in reference to contests, like the "agony of
defeat and the thrill of victory" as ABC News always called it.
But it's just to question of
who has the greater reproductive success
and there doesn't have to be a dramatic contest
So the remaining corners then, are not ordinary Darwinism, but Darwin recognized them, and all are in some way puzzling
and despite this they appear in the living world
and we might think of a Darwinian puzzle as ___
So how could such a behaviour be selected for and preserved?
So let's go to the second corner
Now we have Blue again harming Orange
so we start out the same, A harms B
but as a result
A is also harmed.
Now again there's harm to Orange but there's also harm to Blue
and Hamilton called this the spiteful corner of the universe
we symbolize this with a negative and a negative.
so now we've got two corners to the universe and you can probably predict the other two from these pluses and minuses?
And the spiteful corner seems to be the least likely corner
indeed I could not even find a good photo of true spite
it was mostly selfishness that was represented as spite
and that's because spite is mutually destructive
and it should be strongly selected against
and be very rare. Hamilton indeed said ...
so we don't expect to see spite very often, but it does happen
The third outcome
now we go from harm to benefit - so Blue is benefiting Orange
and as a result Blue also benefits.
So now we mark them both green.
There are benefits all around!
And Hamilton called this the cooperative corner of the social universe.
and indeed the foundation of sociality.
So now that gives us three corners to the universe
And this would appear to be the happiest corner of the universe
and there's just a tremendous number of images showing cooperation
and how good it is and how good it makes us feel to cooperate.
There's various reasons why it can be puzzling or challenging
despite the fact that it's common
commonly expressed in social life
And here's one way to think about it
natural selection is all about changing frequencies of different genes- so when natural
selection is acting on the genetic foundations of behavior
it increases some gene's frequencies at the expense of others.
So cooperation is a plus and plus. But imagine a situation where you have just two alleles
and both are 50% and we can see that both cannot increase simultaneously
so be thinking about that how we get around that puzzle?
The fourth outcome
again Blue benefits Orange
A benefits B but as a result
A is harmed.
So now we have the benefit to Orange
of the harm to Blue.
And Hamilton called this the altruistic corner of the social universe
and now we've got all four corners
and altruism is perhaps the most inspiring corner, it's a theme in much religious thought
in multiple traditions around the world.
And whenever we observe it it often is newsworthy.
But it's even more puzzling than cooperation perhaps.
Because we have to explain sacrificing for others.
And this is an image of a man going into a lake to save a drowning bear, and taking the bear to the shore at the risk of drowning himself
and of course, if he had drowned himself in doing this, he would take himself out of the reproductive game.
So the question is - how can we possibly increase the frequency
of a genetically based behavior in a population if that gene causes uis to destroy ourselves to save others
So this is Hamilton's universe we can say the biggest corner of the universe is the selfish one of ordinary Darwinism
that cooperation is quite common as well and indeed if we're selfish, it's hard to see how social life works, perhaps.
the altruistic corner we expect to be smaller
and the spiteful corner smallest of all.
And what you need to know is how to differentiate those four corners and why they are puzzling.