A new study has affirmed what most of us knew - practice makes perfect, but only if you have some ability. In the nature versus nurture debate, Usain Bolt is still going to run faster than most people no matter how much they practice.

And that goes for musicians too. An analysis of 850 sets of twins leads Zach Hambrick, a Michigan State University professor of psychology, to say both genes and environment matter, "Not only in the sense that both nature and nurture contribute, but that they interact with each other.

Writers such as Malcolm Gladwell argue that experts are almost entirely "made" and that a lack of innate ability can be overcome with enough training. The way to master that cello, in other words, is to practice for at least 10,000 hours. He didn't make it up, plenty of studies and experts said just that

The new study challenges that conjecture and say genes had a major contribution on the musicians who practiced and became successful. For those who didn't practice, there was essentially no genetic contribution.

The study breaks new ground in ascertaining the specific roles of genes. Essentially, it found:

• Accomplished musicians practiced much more than those who weren't accomplished.
  

• That propensity to practice was fueled partly by genetics, which the researchers were able to establish by comparing identical twins, who share 100 percent of their genes, with fraternal twins, who share 50 percent of their genes. The finding suggests genetics influence the sorts of activities we pursue.

• When it came to music accomplishment, genes had a bigger influence on those who practiced than those who didn't.

This has always been assumed. People who are good at something tend to want to do it more, whereas people who are not good at something often get discouraged. Does genetics determine which sports you play? Psychologists have trod on treacherous biological ground by claiming a genetic predisposition for everything from voting habits to car grills to a messy office. 

"Contrary to the view that genetic effects go away as you practice more and more," Hambrick said, "we found that genes become more important in accounting for differences across people in music performance as they practice."