Genetics

It was in 1997 that Henry Plotkin, Professor of Psychobiology at University College London, published Evolution in Mind.  In this he gave a fulsome explanation to Dobzhansky’s assertion that “antecedence becomes cause” – how we think today is largely shaped by the structures in the brain which have developed over enormous periods of time as our ancestors perfected ways of thinking that had enabled successive generations to survive.  Plotkin extended Stephen Gould’s assertion that evolutionary psychology has to be a key part of the explanation for human behaviour.

Geneticists are now reasonably convinced that the human species first split from the Great Apes some seven million years ago.  Since then the human genome has come to differ from the Great Apes by less than 2%.  The vast majority of our genetic composition was shaped before that split.  That 2% difference this is concentrated almost entirely in the nature of the brain – the rest of our bodily structures remains remarkably ape-like.

Seven million years is hard to envisage.  Try thinking of it in terms of generations, each averaging twenty years –this reduces seven million years to a more manageable 350,000 generations.  Can you envisage a family tree of 350,000?  Well, 350,000 is roughly the number of minutes we are awake in a year.  Try thinking of each generation as lasting a minute on that genealogical table of a whole year.  Most of us know only five or six minutes of that year-long story – our parents and grandparents, ourselves, our children, and our grandchildren.  Imagining it like that it seems incredible that the human genome has only changed by a mere 2% over that vast number of successful impregnations.  Over all that time our arms and legs remain very like the ape, but we have very different kinds of brains.

Sarah Blaffer Hrdy of the University of California – Davis in her recent book Mothers and Others; the evolutionary origins of emotional understanding (2009) gives a dramatic picture of “antecedence as cause.”  Hrdy notes that most of us are accustomed to being squeezed and strapped into rows of uncomfortable seats as we settle, along with a further 400 other travellers, into a Boeing 747 and prepare for an eight, ten or twelve-hour intercontinental flight.  Uncomfortable as this can be, there are few instances of passengers assaulting each other, or the flight attendants, or even the pilot and, to the best of my knowledge, I have never heard of one passenger murdering another.  With stiff backs and crumpled knees we proceed down the aisle to disembark in that distant airport.

Now imagine replacing the human passengers with Great Apes.  Even if you were successful in strapping them into their seats all mayhem would quickly breakout.  Unnerved by the experience, many an ape would attack its neighbour.  Ears would be torn off, and blood would flow.  The first ape to figure out how to undo the seatbelt would rush off down the aisle looking for a fight.  Others would follow.  Within an hour or so all would be carnage.

However hard you try to civilise apes by educating their young in the very best Frobel, Steiner or Montessori schools you would not change their nature enough that, when they were adults, they would be able to behave in a sufficiently civilised fashion to survive such an experience.  The reason is simple.  Apes have not inherited from their ancestors those sophisticated structures in the brain that enable us humans to follow the safety instructions and, with a fair injection of empathetic understanding, still walk off that plane a dozen hours later… even exchanging business cards with newfound colleagues!  Apes only understand dealing with the present and only distinguish very simply between friend and enemy.

That is what “antecedence as cause” means…….. and it obviously means a great deal.

See Chapters 2, 3 and 4 of Overschooled but Undereducated