WASHINGTON (AFP) – Scientists have found the reason why blacks dominate on the running track and whites in the swimming pool: it's in their belly-buttons, a study published Monday shows. What's important is not whether an athlete has an innie or an outie but where his or her navel is in relation to the rest of the body, says the study published in the International Journal of Design and Nature and Ecodynamics. The navel is the center of gravity of the body, and given two runners or swimmers of the same height, one black and one white, "what matters is...