The Symmetry of Children's Knees is Linked to Their Adult Sprinting Speed and their Willingness to Sprint in a Long-term Jamaican Study Trivers, R.i Palestis, B.2 & Manning, J.T.3' 'Department of Anthropology, Rutgers University, New Jersey, USA. 2Wagner College New York, USA. ;Applied Sports Technology Exercise and Medicine Research Centre, Swansea University, UK. *Correspondence should be addressed to: Abstract: Jamaican athletes are prominent in sprint running but the reasons for their success are not clear. Here we consider the possibility that symmetry, particularly symmetry of the legs, is high in Jamaican children and that this is linked to high sprinting speed in adults. Our study population was a cohort of 285 rural children (156 boys), mean age 8.18(1.72) years. Symmetry was measured in 1996 and 2006 from the fluctuating asymmetry (FA) of nine traits (six upper- and three lower-body traits) and we constructed an upper and a lower body composite FA trait [Comp ub: FA and Comp lb=FA respectively). We found Comp lb: FA<Comp ub: FA, and both were lower than in comparable Caucasian norms. In 2010 we measured sprinting speed (mean time for 90m and 180m races) in 1 EFTA01130097