Enhancing intelligence
Can parents, employers or the state create environments that will make people cleverer? Professor James Flynn debates this and urges us all to fall in love with ideas
I am best known for documenting the massive IQ gains that have taken place from one generation to another over the past century, the so-called ‘Flynn effect’. My book What is Intelligence? discusses those gains to illuminate the gulf that separates our minds from those of our ancestors in 1900.
Readers may delight in the cognitive history of our time but often they quickly gravitate to the chapters about how to enhance their intelligence and the IQs of their children. The quick answer is by having good luck or making your own luck by falling in love with ideas. This advice rests on two pillars: the plasticity of our brains and the transitory nature of the effects of environment.
Our brains are much more like our muscles than we once believed. The brain does not stop developing in youth. Neurons and their connections reach maximum complexity only in the early 50s. Cognitively complex activities give some protection even against dementia and Alzheimer’s.
Richard Wetherill played chess in retirement and could think eight moves ahead. In 2001, he was alarmed because he could only think four moves ahead and took a battery of tests designed to spot early dementia. He passed them all easily and continued an active mental life until his death in 2003.
Autopsy showed that his brain was riddled with the plaques and tangles that are characteristic of Alzheimer’s. Most people would have been reduced to a state of total confusion.
I do not wish to raise false hopes. Wetherill’s high level of cognitive exercise did not keep his cognitive abilities from declining with age. Cognitive exercise helps all ages and the benefit accrues even if the exercise regime is postponed until later life. But this does not deny the fact that the ageing brain causes everyone’s performance to decline. The active mind will always perform better than the inactive but both will decline in tandem – particularly from age 70 onwards. Hold to the image of the brain as a muscle. At any age, an athlete is better off for training; but however hard you train, your times will get slower with age.
Different areas of the brain are surprisingly independent. Certain neurons spray dopamine in the area immediately surrounding them rather like a sprinkler. Any synapses in the vicinity that have recently been active, that is, have had information passed across them, will react to the dopamine and be strengthened.
Strengthening a particular web of synapses means that it will be easier in the future to fire off those neurons and thus reproduce the same pattern of activity. Damage to the brain is often localised in its effects. Trauma to the pre-frontal cortex vetoes a normal level of on-the-spot problem solving ability, but other undamaged areas allow normal levels of other cognitive abilities.
Just as you can develop the muscles of a swimmer or a runner, you can improve spatial ability without improving verbal ability and memory without improving your mental agility. Taxi-drivers in London, at least those who are both expert and experienced, have brains that are peculiar. They have an enlarged hippocampus, which is the area used for navigating three-dimensional space.
To develop a wide variety of cognitive skills you need a wide variety of exercise. It will be interesting when someone assesses the effects of Kawashima’s brain training regime. A variety of mini-games include solving simple maths problems, counting people going in and out of a house, drawing pictures on the Nintendo DS touch screen, and reading classical literature aloud into a microphone.
The Dickens/Flynn model clarifies the interaction between genes and environment. After infancy, there is a tug of war between two environments: the environment parents impose, which is not directly correlated with the child’s unique genetic endowment; and the environment the child creates by interacting with the world, which does tend to match the child’s unique genetic endowment. With each passing year, a child transcends parental influence and becomes more and more an autonomous actor.
As to why a child’s genetic endowment for IQ is so influential, it is always with him or with her, while quality of environment is much more at the mercy of life history. Parents cannot prevent their child from rebelling against a teacher with whom there is little rapport or getting in with the wrong crowd. Therefore, there is a strong tendency for a genetic advantage or disadvantage to get more and more matched to a corresponding environment. The child who finds schoolwork easy is more likely to see it as a way to excel, become motivated to do more homework, and get extension work from teachers. The child who has to strain to keep up is more likely to get discouraged and spend more time on sport than studies.
Over the school years, the imposed parental environment uncorrelated with genes loses ground to the acquired environment correlated with genes. The twin studies confirm that family environment loses ground with age. The genetic proportion of IQ variance rises from 45 percent in childhood to 75 percent in adulthood. The common environment portion of IQ variance falls from 30 percent to practically zero. The latter reflects living in this family rather than another.
Pre-school interventions also impose an environment on children that is uncorrelated with their genes, usually a uniformly enriched one that includes stimulation through educational toys, books, and so forth. If these terminate when children enter school, the intervention is likely to lose the tug of war even earlier than a child’s parents do.
The most radical form of environmental intervention is adoption into a privileged home. Adoptive parents often wonder why the adopted child loses ground on their natural children. If their own children inherit elite genes and the adopted child has average genes, then as parents slowly lose the ability to impose an equally enriched environment on both, the individual differences in genes begin to dominate.
University education is a partial attempt to impose an enriched environment on students regardless of their genetic differences. It too will see its effects on IQ fade unless quality of environment is maintained, for example, if thanks to a good university education a student of average ability qualifies for a cognitively demanding profession. Then the job takes over the university’s role of imposing duties that foster the intellect. The non-IQ effects of university education are much more likely to be permanent than the IQ effects. The contacts made at a good university may confer an enhanced income and socio-economic status throughout life.
None of the above applies mechanically to group differences. The fact that ethnic groups attended the same schools and yet emerge with different IQs does not mean that the IQ difference between the groups is genetic. The different subcultures of groups affect both of the two environments competing with one another in the tug of war. Parents in both groups may impose an early environment that ignores genetic differences between their children, but if the parents in one group are largely poor solo-parents, children from the two groups may enter school with very different IQs. If other environmental handicaps take over at each state of life history, a teenage subculture that is atypical linguistically and more prone to gang membership, an adult world in which many go to prison and most have jobs that make few cognitive demands, then an environmentally induced IQ gap between the two groups will persist into old age.
The cognitive advantages of a good childhood environment tend to fade once the child becomes autonomous. You can always hope that your children will have good luck in the sense that surrogate parents provide them with what amounts to a favourable environmental intervention throughout life. Tracing a life history of that sort will show how chancy that is.
A girl is born with average genes for cognitive ability in a privileged home. Good books and help with homework give her a positive attitude to school. She goes to a good high school and is fortunate enough to make friends, most of whom aspire to professional careers. She gets the marks needed for entry into a decent university. She has to work harder than most but has her heart set on getting into law school. Her marks get her in without much to spare, but once there she profits from the fact that no one with a reasonable education who works hard fails to graduate. She is lucky enough to get into a good firm where she has challenging work and she marries a colleague with intellectual interests. Her friends from college, her workmates, her husband, and her husband’s friends dominate her social interaction and constitute a sort of cognitive cocoon. It gives her a sheltered cognitive environment throughout life just as her parents did when she was a small child.
This degree of luck would be very rare. Note that even if she marries a fool and regresses toward his level intellectually, he and she may be wealthy fools, so her good start has given her permanent affluence if not permanent mental acuity.
A better way to improve on your genetic endowment is to make your own luck. Take running. Rather than hoping that a happy chain of circumstances will force you to train throughout your life, you can develop a love for running and train without compulsion. This will not override genes entirely, of course. There are runners I cannot beat even when I train more than they do. But I can run rings around every couch potato within 20 years of my age.
Some chess grandmasters can play 40 games at once while blindfolded. What differentiates them from other expert players does not seem to be raw talent but persistence in seeking cognitive challenge. Having mastered chess after an initial effort most of us relax. Others never desist from effortful study, that is, from continuously taking on challenges that lie just beyond their competence.
The things parents do at present for their children are all worth doing: reading stories, good diet and exercise, good schooling. But somewhere along the line children must fall in love with ideas, so they will want to marry someone intelligent, seek out friends who are alert, earn their living doing something cognitively complex, develop leisure interests that are challenging. And the best way to get them to fall in love with ideas is to fall in love with ideas yourselves. Children respond very differently to being simply told to read and living with parents who read and say how excited they are by the experience.
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