The Sex Dimorphism Ratio in our lifespan

Abstract

The purpose of this study is to examine the Sex Dimorphism Ratio (SDR) for a wide range of age groups in two environments, the suburbs of Los Angeles and Taiwan, which differ in height distribution. Using statistics, we examine if SDR will alter due to the change in woman’s reproductive viability. Two-way Analysis of Variance (ANOVA) in the form of multiple regression analysis with dummy variables and traditional regression analysis are applied. The results show that SDR approximately follows the required normal distribution, there is no interaction between age and environment, and there is no difference in SDRs among the 36 age groups. The only factor that affects the mean of the SDR is the environmental difference. The results imply that SDR remains constant throughout our lifespan despite changes in our personal reproductive viability. The ideal SDR is not fixed because different height probability distributions in different environments may have different optimal SDRs. The minimum SDR stays fairly constant, though statistically different from two different environments in our study. The maximum SDR from one environment in this study is much higher than that from the other.