UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Furthering our understanding of asexuality : an investigation into biological markers of asexuality, and the development of the Asexuality Identification Scale Yule, Morag Allison


Human asexuality is defined as an absence of sexual attraction to anyone. Approximately 1% of the population is thought to be asexual. However, there has been a paucity of research into correlates of asexuality as well as into how asexuality is best conceptualized. This is in part due to logistical difficulties in recruiting and identifying representative samples of asexuals. Because of the low prevalence rate of asexuality, and the relatively recent emergence of asexual communities, many individuals who lack sexual attraction may not self-identify as asexual. Previous studies have recruited asexual participants via online web-communities, and relied on self-identification as asexual, which may result in non-representative sampling. The purpose of this study was two-fold. Firstly, in response to continuing debate as to whether asexuality is better understood as a sexual orientation or as a sexual dysfunction, Study 1 aimed to investigate the claim that asexuality would best be conceptualized as a sexual orientation in a large internet sample. Biological markers such as finger length ratios, handedness, and older siblings have may be related to prenatal development, and have been linked to sexual orientation. Asexual men and women were more likely to be non-right-handed than their heterosexual counterparts, and there were significant differences between sexual orientation groups on the number of older brothers and older sisters, and this differed depending on handedness. We found no significant differences between sexual orientation groups on measurements of 2D:4D ratio. However, this is likely due to the relatively small sample size. This is the first study to test and provide empirical support for an underlying biological etiology to account for the lack of sexual attraction characteristic of asexuality. Study 2 presents the development of a brief, self-report measure of asexuality. Initial testing of questionnaire items identified by an expert panel was followed by a study aimed at further refining the questionnaire. Based on discriminant analysis as well as reliability and validity tests, a 10-item measure was identified, and was found to be able to distinguish between sexual and asexual individuals. This measure will be used to obtain more representative samples of asexuals in future research.

Item Media

Item Citations and Data


Attribution-NonCommercial-NoDerivatives 4.0 International