Sexual Dysfunctions in Men: An Evolutionary Perspective

Successful sexual intercourse is a prerequisite for successful reproduction, a fact that translates into strong evolutionary pressures being exercised on mechanisms that regulate sexual functioning to work optimally. In effect, selection forces would remove from the gene pool any alleles that predispose for sexual dysfunctions, limiting their prevalence to very low levels. But this did not happen with epidemiological studies indicating that sexual dysfunctions are common, with approximately one in three men facing such a difficulty. This raises the question why evolutionary forces have allowed such variation in sexual functioning given its importance in reproduction. The present paper attempts to address this question by applying three evolutionary models on anthropological and historical evidence that depicts the ancestral human condition. It is argued that the high prevalence of sexual dysfunctions in men is predominantly explained by the mismatch between ancestral and modern environments, with selection forces not having sufficient time to optimize sexual functioning mechanisms to the demands of modern conditions. The proposed evolutionary framework is employed to derive predictions which are examined against the available evidence on sexual dysfunctions.