Support for a Fluid-Continuum Model of Sexual Orientation: A Large-Scale Internet Study

Abstract

In a study with 17,785 subjects obtained over the Internet from the United States and 47 other countries, Kinsey's hypothesis that sexual orientation lies on a continuum was supported. Self-identifications of subjects as gay, straight, bisexual, and other corresponded to broad, skewed distributions, suggesting that such terms are misleading for many people. Sexual orientation range—roughly, how much flexibility someone has in expressing sexual orientation—was also measured. The results support a fluid-continuum model of sexual orientation, according to which genetic and environmental factors determine both the size of the sexual orientation range and the point at which an individual's sexual orientation is centered on the continuum.

Keywords:

• sexual orientation
• Alfred Kinsey
• sexual orientation range
• sexual orientation test
• mean sexual orientation
• sexual orientation continuum
• fluid-continuum model of sexual orientation
• Epstein Sexual Orientation Inventory
• ESOI

Acknowledgments

This article is based on a paper presented at the 50th annual meeting of the Society for the Scientific Study of Sexuality, Indianapolis, Indiana, November 2007, cosponsored by The Kinsey Institute. Some of the data were also presented at the 21st annual meeting of the Human Behavior and Evolution Society, Fullerton, CA, May 2009. The authors thank Traci Castleberry for help in preparing an earlier version of the manuscript, as well as P.D. Moncrief, Randall Sell, Robert Spitzer, and James Weinrich for comments.

Notes

1. The term “gay” will be used inclusively for gay/lesbian throughout this article, unless otherwise specified.

2. The Kruskal-Wallis H test is appropriate here because the test scores are on an ordinal scale, not on an interval or ratio scale. Nonparametric statistical tests of this sort, such as Spearman's rho (ρ) and the Mann-Whitney U, are, consequently, used throughout this article.