Posted by Danny TarlowFrom the article:
Now how does this elucidate the elusive X-Factor? My esteemed colleague Dean Keith Simonton  offers a nuanced genetic model of talent that I think is relevant. Simonton has argued that additive models of talent are too simplistic (see last post for an additive model of music talent). It's too simple to say that practice + music ability + high IQ equals musical ability. No, Simonton says that talent, especially in complex domains, is better represented by a multidimensional and multiplicative model.http://blogs.psychologytoday.com/blog/beautiful-minds/200806/the-nature-genius-i-the-genetics-the-x-factor When you hear the term multiplicative model, you should think of AND, and when you hear the term additive model, you should think OR. Essentially, ability in any given task is better modeled by saying that you have to be strong in every relevant trait than by saying that you can make up for a lack of strength in one trait with more strength in another. It is very hard to make up for a lack of musical ability with a high IQ and lots of practice (if your goal is overall musical achievement), for example.