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Showing posts with the label game theory

What do they tell us about our species?

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Curiously, I think the answer is that human males are generally monogamous. Before getting on to that we should ask: what is the excess adipose tissue carried by females of the human species actually for?  There are two naive answers which I've heard expressed in the past: To provide milk for the human infant To attract a mate Neither of these explanations hold water.  Every other mammal that I'm aware of only has swollen glands whilst the offspring are young enough to breastfeed. At all other times the females look more or less similar to the males.  The second explanation leaves open an obvious question too.    Why should a male be attracted to these things in the first place? What does seem to be true, is that - all other things being equal - possession of the aforesaid is an encumbrance, as any well-endowed cave-woman that has ever tried to flee a sabre-toothed tiger might attest. There are cases in nature, however, where encumbrances are carried purely to i

Black and Yellow

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Source: https://www.pexels.com/photo/black-and-yellow-snake-65296/ Why does black and yellow signal danger?  Is it just an arbitrary convention or is there some explanation for this particular choice of colours? The answer may lie in Game Theory.  We can think of evolution as an iterative game played by the following 3 players: The genome of poisonous prey-like animals The genome of non-poisonous prey The genome of predators Most non-poisonous prey camouflage themselves to some degree or another, for example by adopting the colour of chlorophyll or the colour of mud.  Poisonous animals often do the exact opposite and choose colours that stand out, like yellow and black. Why shouldn't poisonous animals use camouflage colours too?  It is often claimed that this is done to help the predators for spot them, but that doesn't make much sense.  If the snake shown in the picture were green and brown it would still be possible for predators to learn not to eat it because

Penalty Shoot Out

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P(l)ayoff table What's the best strategy for taking or defending penalty kicks?  Essentially there are three options for each player: go left, right or centre.  But what proportion of the time should each player take each of these options? We can try to answer this with a toy model and see what happens.  In this model the goal is always saved if the choices match and is always conceded if they don't.  What makes this model interesting is the "utility" of each outcome to each player. We could choose 1:0 to the striker for a goal and 1:0 to the goalie for a save, but we can make things more realistic by applying a bit of psychology.  Let's face it: if the goalie doesn't move and the ball goes left or right s/he will look pretty stupid.  For that reason I have given the goalie a minus one in this case.  Likewise if the striker shoots towards the middle and the goal is saved then the striker will look silly, so in that case he or she gets a minus one inste