The Guardian has an excellent article on why news stories touting a gene for a particular psychological trait, like intelligence, optimism or dyslexia, are usually misguided.
The piece is a fantastic potted guide to how science goes about untangling the effects of genes and the environment and how this applies to the increasingly popular attempt to link genetics to personality, thinking and behaviour.
What are the implications of all this for the stories we hear in the media about new genetic discoveries? The main message is that we need to be aware of the small effect of most individual genes on human traits. The idea that we can test for a single gene that causes musical talent, optimism or intelligence is just plain wrong. Even where reliable associations are found, they don’t correspond to the kind of major influences that we learned about in school biology. And we need to realise that twin studies, which consider the total effect of a person’s genetic makeup on a trait, often give very different results from molecular studies of individual genes.
Don’t be put off by the picture of Jedward. Not all twin studies are quite so gruesome.
Link to article on myth of ‘a gene for things like intelligence.’