Neeru Jayanthi, M.D., Associate Professor, Department of Family Medicine, Orthopaedic Surgery and Rehabilitation, Medical Director, Primary Care Sports Medicine, Loyola University Chicago, Stritch School of Medicine, says three studies of college athletes shows that they don't specialize earlier or more than those who don't play sports in college, that they played multiple sports, even in high school, and that the biggest predictor of whether a youth athlete will play sports in college is whether they have a first degree relative (i.e. parent or sibling) who played college or professional sports; in other words, genetics.