Jamaican Symmetry Project: Long-term study of fluctuating asymmetry in rural Jamaican children

Fluctuating asymmetry, small deviations from perfect bilateral symmetry, is negatively correlated with health and positively correlated with sexual se lection in human adults, but the accumulation, persistence, and fitness imp lications of asymmetries during childhood are largely unknown. Here, we int roduce the Jamaican Symmetry Project, a long-term study of fluctuating asym metry and its physical and behavioral correlates in rural Jamaican children . The project is based on an initial sample of 285 children (156 boys and 1 29 girls), aged 5 to 11 years. We describe the design of the project and th e methodology of measuring 10 paired morphometric traits. All traits except hand width showed fluctuating asymmetry. Fluctuating asymmetries of the le gs tended to be related and were less than half as great as fluctuating asy mmetries of the arms and ears. Therefore the legs may show high development al stability resulting from selection for mechanical efficiency. A fluctuat ing asymmetry composite score revealed that boys have significantly lower f luctuating asymmetry than girls and that this effect resides mainly in the elbows. There were significant positive relationships between composite flu ctuating asymmetry and age, height, and weight, but multiple regression ana lyses showed that age was negatively related to fluctuating asymmetry, wher eas body size was positively correlated. These findings are compared with r esults from recent English studies.