Mind Hacks

For those of who you particularly enjoyed the Prospect article on the interaction between environment and genetics in promoting certain mental states and behaviours, Nature Reviews Neuroscience has an in-depth review article on how neuroscience is helping understand this complex process.

If you haven’t got time to get down and dirty with a full-on review article though, Brain Ethics has a fantastic summary that captures the main points.

Link to full text of Nature Reviews Neuroscience article.
Link to Brain Ethics article.

Continuing our IQ theme, the New York Times has a fascinating article on the contributions of genetics and environment to IQ and argues that the effect of the environment becomes much more crucial for those from low-income backgrounds.

[Psychologist Eric Turkheimer] has a reputation as a methodologist’s methodologist. In combing through the research, he noticed that the twins being studied had middle-class backgrounds. The explanation was simple – poor people don’t volunteer for research projects – but he wondered whether this omission mattered.

Together with several colleagues, Turkheimer searched for data on twins from a wider range of families. He found what he needed in a sample from the 1970’s of more than 50,000 American infants, many from poor families, who had taken I.Q. tests at age 7. In a widely-discussed 2003 article [pdf], he found that, as anticipated, virtually all the variation in I.Q. scores for twins in the sample with wealthy parents can be attributed to genetics. The big surprise is among the poorest families. Contrary to what you might expect, for those children, the I.Q.’s of identical twins vary just as much as the I.Q.’s of fraternal twins. The impact of growing up impoverished overwhelms these children’s genetic capacities. In other words, home life is the critical factor for youngsters at the bottom of the economic barrel. “If you have a chaotic environment, kids’ genetic potential doesn’t have a chance to be expressed,” Turkheimer explains. “Well-off families can provide the mental stimulation needed for genes to build the brain circuitry for intelligence.”

This interaction between economic background and mental functioning has now been replicated in a number of studies looking at everything from mental illness to criminal behaviour (e.g. see Christian’s previous post).

It seems that the simple summing of genetic and environmental effects is no longer a valid way of understanding how we develop, as the duration, quality and frequency of different life experiences seem to have unique influences on the expression of our inherited traits.

Link to New York Times article ‘After the Bell Curve.
pdf of Turkheimer’s paper.

Psychoanalyst Adam Phillips is interviewed in The Guardian about the paradox of chasing happiness and the negative effects of emotional idealism.

Phillips argues that trying to eliminate all sources of stress in your life is a pointless exercise and we should become better at tolerating difficult situations if we are to be become fully content.

I tell Phillips that at my workstation books with the word happiness in the title arrive unbidden by the hour. They include: Daniel Gilbert’s Stumbling on Happiness, Richard Schoch’s The Secrets of Happiness, Darrin McMahon’s The Pursuit of Happiness, Richard Layard’s Happiness: Lessons from a New Science and Jonathan Haidt’s The Happiness Hypothesis. Do you read these books? “I’ve looked at them. They seem to me to be the problem rather than the solution.”

Phillips also gives his take on the current focus on CBT as the psychological therapy of choice and the use of psychoanalysis as a long-term therapy for people with socially turbulent modern lives.

Link to article ‘Happiness is always a delusion’.

American Scientist discusses the trend for changes in how well people score on intelligence tests and notes that the Flynn effect, whereby the population has been scoring increasingly well on intelligence tests over time, seems to be slowing down or reversing in some places.

It is well-known is psychology that performance on cognitive tests changes over time and across populations, which is why the most widely used tests (particularly the Wechsler series) have different versions for different countries, and are re-released every few years with new comparison data.

An IQ score is always relative to the average performance of the rest of the population, so an IQ of 100 always means you score the same as the average of the population on a current test.

As new tests are released, this average may shift, so it is difficult to directly compare IQ results from previous versions of a test.

On old tests, however, it was noticed by Flynn that people were scoring better by about 3 points per decade. The American Scientist article notes that this effect is starting to slow down or reverse in some places though.

Does this mean we’re becoming less intelligent? Probably not. It likely reflects the fact that the skill set of population is changing and that we become practiced at different tasks at different rates as modern life develops.

As an aside, IQ tests considered trustworthy by psychologists rarely go above 160, so anyone quoting a 160+ IQ is likely to be talking nonsense.

Link to article ‘Smart as We Can Get?’.
Link to Wikipedia article on the Flynn effect.