During the last 20 or 30 years research in cognitive sciences, neurobiology, evolutionary studies, genetics, and systems theory has started to explain just how it is that the brain makes up its mind. We are understanding better how our preferred ways of doing things have been shaped by what Henry Plotkin.’ Professor of Psychology at University College London, calls “evolution in mind”. Psychology, he argues, has been slow to recognise that our brains are as much shaped by evolution as are other parts of our anatomy.
The easiest predisposition to understand is the young child’s ability to learn language, apparently spontaneously. By the age of 3 or 4 children have little difficulty in speaking their own language, while those who live in multi- ethnic environments can frequently speak 2 or 3 more languages by the age of 5. In comparison to the difficulty I had in learning Latin at the age of 16 the young child’s ability to learn language seems amazing. It is.
We now know some of the reasons why this is so. In the ancestral environment from which we came life was highly precarious. To increase the chances of survival people banded together into small groups and, in their search for new food sources, became of necessity nomadic and collaborative. We humans evolved as a “small group” species, happiest, it seems, when we work in teams and multi-task. It is no accident that cricket and soccer teams have 11 players or that there were 12 disciples, or that a jury comprises 12 people. Indeed, when more than 15 people make up a nation’s Cabinet they frequently split into warring factions. Add dependents – women, children and the old – and our ancestors frequently had to deal with no more than 60 people in a lifetime.
Latest research suggests that humans first developed the ability to speak about 130,000 tO 150,000 years ago. It was something to do with the way the larynx – the voice box – moved just far enough down the throat that we were able both to breathe and control the sounds we made, all at the same time. Coincidentally, by that time our ancestors had learnt how to make fishhooks – so for the first time fish in significant quantities entered the human food chain. Fish are rich in amino acids and the brain desperately needs such fatty acids to create what is called “neural sheathing”. Very simply, this improved the insulation around the dendrites, which largely keeps ideas flowing in the preferred direction.
Once humans learned to talk we developed the most awesome new survival techniques. Let me explain. The person who can’t talk, and can’t understand what is said to them, is totally dependent on their own experiences to guide their actions. They know nothing they have not personally experienced. But the person who can talk can add enormously to their own experiences by adding the ideas told them by others. Language enable us to develop a kind of “group brain’ – our thoughts are more than just our own experience.
Every child is born with this generic language predisposition. Just what they do with it depends on the culture into which they are born. Research four years ago carried out by the Kellogg Foundation in Michigan into what are the best predictors of success after the age of 18 showed that it was the quality and quantity of dialogue in a child’s home before the age of 5 that was four times more significant than any other factor, far more significant than either the primary or secondary school. In reality our ancestors knew this long ago. St. Augustine was said to have remarked “I learnt most, not from those who taught me, but from those who talked with me.” That monk understood the proper balance between formal teaching and spontaneous learning. This is the balance we have to regain.
For the past six years I’ve been the President of an international research foundation, networking the findings of research in various disciplines. You can find it on our website www.211eam.org.
Marion Diamond is an eminent neurobiologist from Stamford. She was one i of the team who carried out the autopsy on Einstein’s brain. As a young doctoral student she worked on rats’ brains (which, disconcertingly, have distinct similarities to the human brain). Not being rich she had to carry out a lot of her work at home where she was also bringing up a young family.
She did what is now a standard research procedure. She had two cages of rats, one containing toys and one without. Every week she took a rat from each cage and examined its brain. Week after week she weighed these brains. Consistently the brains from the rats in the enhanced environment (the ones with toys to play with) were 10% heavier than those of the other rats who had no playthings. This was the result she had expected. Not that brain weight is an exact measure of intellectual potential, but it’s a guide.
Unbeknown to Marion, her children thought the whole experiment was very unfair on the rats, so they started a rescue mission, releasing a number of rats over a period of several weeks and letting them have the run of their own bedrooms. When Marion discovered what was going on – good scientist that she was – she realized she now had a third colony of rats to study. Unbeknown to her children she then started to collect free-range rats from the children’s bedrooms. She carried out the same experiment. Much to her delight and to her scientific satisfaction – and, yes, you’ve guessed it – she found that these free range rats had brains more than 10% heavier again than the artificially stimulated rats, and, of course, more than 20% heavier than the rats in the sterile environment. Rats, if you like, need more than the simulated activity of the classroom, as do human youngsters. Early learning is as much to do with the emotions as it is with the intellect.
Let me give you a simple analogy. Many of you will remember, not so many years ago, that when you bought a new car you could never go more than 30mph for the first 500 miles. To your chagrin you had to display a warning “Running in – please pass”! Then for the next 500 miles you had to keep to 40mph and so on. When eventually the engine was run in you could drive as fast as you liked. But woe betide the well being of your engine if you tried to go too fast too soon. Those first 2000 miles of driving were, literally, a matter of testing and rounding off the edges.
The brain is just like that too. Very few of you will remember anything from your first three years of life (other than highly traumatic events). For long years academics and educators took this to mean that such years were not particularly important. That was a terrible mistake; these are the years in which the brain is running itself in, and it’s on the quality of this experience that future learning depends.
Very recently neurobiologists at San Diego have started to use non-invasive functional MRI scans to look at the way children’s brains develop below 18 months of age. Their initial findings are intriguing. Those youngsters who come from homes which, in terms of mental stimulation, could be thought of as largely sterile (too much unsupervised TV, few toys, virtually no reading) were found to have very linear dendrite structures with relatively few interconnections. However, those children coming from homes where there was a variety of stimulation and talk had an early dendrite structure that was full of bifurcation and interconnection. Einstein’s brain was not found to have been extraordinarily heavy; what it did have was an exceptionally large number of glial cells that facilitated multiple bifurcation of the dendrites. It’s the making of connections that is so important, and the earlier children start doing this the better brains they will build for themselves.