The relative importance of nature and nurture for various forms of expertise has been intensely debated. Music proficiency is viewed as a general model for expertise, and associations between deliberate practice and music proficiency have been interpreted as supporting the prevailing idea that long-term deliberate practice inevitably results in increased music ability.
An experiment examined the associations (rs = .18–.36) between music practice and music ability (rhythm, melody, and pitch discrimination) in 10,500 Swedish twins. The researchers found that music practice was substantially heritable (40%−70%).
Associations between music practice and music ability were predominantly genetic, and, contrary to the causal hypothesis, nonshared environmental influences did not contribute. There was no difference in ability within monozygotic twin pairs differing in their amount of practice, so that when genetic predisposition was controlled for, more practice was no longer associated with better music skills.
These findings suggest that music practice may not causally influence music ability and that genetic variation among individuals affects both ability and inclination to practice.
This according to “Practice does not make perfect: No causal effect of music practice on music ability” by Miriam A. Mosing, Guy Madison, et al. (Psychological science XXV/9 [September 2014] pp. 1795–1803).
Above, the identical twins Laura (left) and Charlotte Carrivick, who perform as The Carrivick Sisters; below, Derrick Davis and Tom McFadden discuss the importance of genetics (an article about their work is here).