Monday, October 20, 2014

Game Theory: How Humans Changed the Rules

To know who we are we need to understand how we differ from animals.  And the best way to do that is to compare ourselves with the animal that we are genetically closest to.  This would be the chimpanzee,  one of the three African great apes.  We share 95 percent of our genetic ancestory with chimpanzees.  It was about six million years ago that our ancestors and their ancestors parted company.

Adult chimpanzees are about two thirds the size of  humans, they have much smaller brains, but there huge shoulder muscles and their long powerful arms  make them vastly stronger than any human could ever be. They look cute on TV, but they have canines that are meant to be used and they are far better weapons than human teeth. Humans are pipsqueaks compared to chimps, but we make up for it by being better cooperators.

Chimpanzees live under the constant shadow of the alpha male.  The dominant male uses his superior strength to throw his weight around and intimidate everyone else in the group.   Meanwhile other male chimps, while behaving submissively,  actually would love to turn the tables on alpha if they could.

Female chimps are entirely on their own when it comes to feeding themselves and taking care of their kids.  Where is the father?  Busy maintaining his alpha status or if he isn’t the alpha, he’s busy scheming with others on how to take over alpha’s status.  

This kind of behaviour is present in humans - in office politics for instance,  but the difference between us and the apes is that in all human societies the majority of adult humans live in pair bonds where children’s paternity is known.  

The dilemma of how to engender cooperation among sexual competitors was solved in a single stroke with the establishment of the nuclear family.  This arrangement offered almost every male a chance at reproduction, hence incentives to contribute to the common good.  We should look at the human pair-bond, therefore, as the key to the incredible level of cooperation that marks our species.   Frans De Waal,   Our Inner Primate

I’ve never met Frans De Waal, Primatologist, and author of the above quote. I hope that  I am honouring him, rather than embarrassing  him, when  I say that I believe that this is the single most important idea in human history. At the same time, I would like to say, that I have a slight  difference with the way he puts it, (more on this later.)  But overall I think it stands as good as any explanation for what constitutes the ground of human civilization.  

Really?  What I am saying is, the fact  that human pair-bonds replaced the alpha male is the key to understanding the difference between humans and animals.  We still have the alpha male in us, but as humans we are constantly controlling the alpha by social conventions, internalization of morals and even by collective intervention, because that’s what we do.  

Humans became human by cooperating together to take down the alpha.  Before that cooperation, the alpha was always replaced by another alpha.  Only cooperation in common made human pair bonding possible.   The easiest way to see this is contained in the theory of games,  because it’s the most convincing way to see how altruistic behaviour became possible in a Darwinian world.

In order to think about life productively we have to simplify it, and having simply:  players, a set of rules, moves, turns, and outcomes,  gives us the basics of the evolution of any type of behaviour.

All the world's a stage, and all the men and women merely players: they have their exits and their entrances; and one man in his time plays many parts, his acts being seven ages.  William Shakespeare.

Change one word in Shakespeare’s quote, from “stage” to “game”, and it would make a pretty fair description of game theory, the mathematical theory used to explain the evolution of human behaviour.   

Shakespeare does well to include the idea of ages.  We often associate games with youth, because we play many games in our youth as preparation for adulthood.  Games exercise both our minds and bodies.  Humans have exceptionally long childhoods compared to other animals.  It takes a long time to learn all the rules and habits that go into being an adult, so the simplified representation of life activities in games provides a virtual environment in which to practice, as well as providing a softer landing for our youthful mistakes.

To play a game is to play by the rules of the game, implying the ability to follow rules and commands.  To follow a rule or command is to act in a way that takes other’s interests into account.  Rules exist to facilitate playing the game and to ensure fairness for all the players.  The fact is, playing games, especially sports games,  helps instill the ability to act collectively and prosocially.  

In life there are forced moves.  But one of the things that more often distinguishes games is that our participation is voluntary.  We agree to play by the rules because we believe that the rules are fair and the other players are playing by the rules too.  If we perceive others as having broken the rules the game usually breaks down.  And no-one wants to play if they know the rules are fixed.

Our lives are a sequence of behaviours, and we almost always internalize rules of behaviour that guide us. The possible behaviours are endless, but Mother Nature carves out our basic game-plan:  You are born, you grow bigger, you learn things, you become productive, you mate, you raise children, you die.  Some of these sequences are forced moves that nature imposes.  Still, at every step of the way we make choices and we base those choices on rules that we have internalized,  unconsciously or consciously.

In the game of evolution, “the struggle for existence”  as Darwin called it,  the winner is the one who has the most offspring.  Who has the most offspring depends on an individual’s genetic heritage and the state of the environment.  As the environment changes, due to, say, climate change, this will highlight the differential abilities of individuals to reproduce.  

Evolution tests alternative strategies for the ability to survive and reproduce…... The key point in the evolutionary game theory model is that the success of the strategy is not just determined by how good the strategy is in itself,  it is a question of how good the strategy is in the presence of other alternative strategies, and of the frequency which other strategies are employed in competing populations.    Elinor Ostrom,     Governing the Commons

Elinor Ostrom, nobel-prize winning American economist, and the author of that quote, is on to something very important here.  Humans evolved from primate groups.  Our closest relatives, the great apes live in groups where dominant individuals control access to reproductive sex and the choicest food.  In such groups, altruism, the practice of helping others at the expense of oneself, is a losing strategy because of the superior reproductive success of the alpha male.  It generally pays to be selfish if you are a chimpanzee.  

On the other hand, in human societies we’ve literally changed the rules: we disapprove of and avoid selfish behaviour,  and social institutions are largely structured around creating incentives that inhibit selfishness and promote other-regarding behaviours. How were we able to do this, if Darwinian evolution is pushing us the other way?

E.O. Wilson, the founder of Sociobiology, and author of a number of books about human nature, argues that humans are eusocial,  that we have changed the rules from natural selection on the level of individuals to multi-level selection,   by creating cohesive groups of kin and unrelated allies, where  altruistic behaviours result in certain groups out-competing others.

Wilson points out, animals that can act collectively have an enormous advantage over individual animals of other species.  This is borne out in the ascendency of ants, termites, and other social insects and, of course, with humans.

  How did we change the game to create human society? Anthropologist Christopher Boehm in his book Moral Origins, The Evolution of Virtue, Altruism and Shame, argues that our ancient ancestors deliberately eliminated overly selfish deviants from the gene pool in order to make altruism work.  

Boehm notes that in egalitarian societies there are many social techniques of peer pressure:  gossiping, ridicule,  and social distancing, for instance,  that are widely used to “socialize” behaviour.  Most of the time these work, and we all internalize social dos and don’ts.

 But it appears that some aspiring alphas, the most destructive ones, with no conscience and an inability to follow social rules, were deliberately taken out of the gene pool by general social consensus in order to avoid social fission.

To this day, hunter-gatherers will agree by consensus to banish or assassinate overly violent and intimidating members of their own community. That may sound harsh from our modern point of view, but in light of the absence of police and law courts in hunter-gatherer society, it’s probably a reasonable way to prevent Hatfield vs. McCoy feuding.

People agree to follow rules when they believe that others are doing the same.  When this happens social institutions encourage prosocial behaviour.  When people don’t trust that others are going to be fair, then they too abandon the rules  and social institutions break down.   The latter situation is basically what goes on in a Chimp alpha-male- run society.

The moral “rules” in Chimp society are  “Might makes Right”. There are no other rules, in most circumstances.  Humans play games “just  for the hell of it” but  chimpanzees don’t play human games unless there is some external reward involved.  Chimps won’t follow rules for their own sake, as humans do, because they know that the alpha male does not honour the rules.  

Somehow, our ancestors managed to collectively  overthrow the dominant,  probably by the technological advance of spears and stone weapons.   Their goal was not the ambitious one of creating civilization, it may have  been just the desire to pair themselves off in a fairer system.  They wanted more stable longer lasting relationships and to avoid the constant fighting over sexual dominance.

There is evidence for this is  in our physical bodies.  Male chimpanzees are physically many times more powerful and capable of killing or wounding than human males.  We don’t have super-powerful shoulder muscles and huge fangs because we get things done through cooperation.  

For whatever the motives, overthrowing the alpha created a level playing field where pair-bonding,  language,  and moral rules,  such as “Do unto others”  became possible.  But the culture of  levelling became an ongoing process of detecting and punishing cheating, a preventative to avoid new alpha males from emerging.

In becoming human, we internalized prosocial emotions that  guide our behaviour and that help us empathize with others in our group.  The group can collectively act to police each individual’s behaviour, looking for and detecting cheating, punishing cheaters, and keeping the general trust.  It then pays to play by the rules, because one can reasonably expect that everyone else will play fair, given the costs of exposure.  

Now let’s hear that paragraph of de Waal’s again:   The dilemma of how to engender cooperation among sexual competitors was solved in a single stroke with the establishment of the nuclear family.  This arrangement offered almost every male a chance at reproduction, hence incentives to contribute to the common good.  We should look at the human pair-bond, therefore, as the key to the incredible level of cooperation that marks our species.

When early humans took out the alpha male and replaced him with couples, they made morality possible, where before it had been “Might makes right”.  Once the rules of the game were changed through collective action the Darwinian game of survival became the human game of cooperation and mixed cooperation and competition with other groups of humans.  This led to a steady gain in human population over time and to the development of religion, philosophy and science.

Now, doesn’t that sound better than “survival of the fittest” and “makers and takers”?   Morality evolved from early human behaviour, but it evolved when our ancestors collectively decided to take down the alpha, and replaced him with monogamy.  

It appears that instituting monogamy was more than just a “single stroke”- It  involved collective hands-on maintenance.  In order to keep alpha males from re-taking over, our ancestors had to  collectively institute powerful social controls, with effective monitoring of behaviour, detection of cheaters, and timely and appropriate punishment.

And as Christopher Boehm shows, in Hierarchy in the Forest, his book describing the comprehensive study he made of hunter-gatherers,   all contemporary small-scale egalitarian societies share these social control networks.  He calls them “moral communities”.

The fact that our very ancient hunting and gathering ancestors were able to control and channel alpha male behaviour, and generations succeeding were able to do this, means that we have them to thank for morality, religion, and science, not to mention our very existence.

It was our ability to collectively and consciously change the rules of the game, from the survival of the fittest, to within-group and between group cooperation,  that ultimately distinguishes us from all other animals.