Circular and linear modeling of female sexual desire and arousal

There is debate in the scientific literature regarding which model most accurately represents the female sexual response. Traditionally, sex research has been conducted within the framework of the linear sexual response model proposed by Masters and Johnson, modified by Kaplan, then Robinson. Criticism of linear models prompted the development of a composite model of the female sexual response by Basson et al., which included linear and circular pathways. This review aims to systematically assess published studies to determine the extent to which circular and linear models or pathways reflect the female sexual response. Medline, EMBASE, and PsychINFO databases were searched for original data papers and review articles. Inclusion criteria were that articles were published since 1990, in English, and compared linear and circular sexual response models or addressed aspects of these models. Reviews were required to be systematic and include a meta-analysis. Of the 898 studies identified through the initial literature search, 13 original studies and one review met the inclusion criteria. Two studies directly compared models providing limited evidence that most women identify with linear sexual response pathways. However, there is increasing evidence that circular pathways may accurately reflect some aspects of the female sexual response. Further comparative studies are encouraged.