Cluster Analysis of the Klein Sexual Orientation Grid in Clinical and Nonclinical Samples: When Bisexuality Is Not Bisexuality

Abstract

A cluster analysis of the Klein Sexual Orientation Grid (KSOG) in three samples (Internet-recruited men and women; HIV study men) resulted in objectively determined 4- or 5-cluster classifications (such as “bi-heterosexual” or “bi-bisexual”). Group means and standard deviations on the KSOG's 21 items revealed that overtly erotic items (sexual fantasies, sexual behavior, sexual attraction) and self-identification items were more uniform within groups than social items (emotional preference, socialize with, lifestyle) were. The bisexual cluster in the HIV sample was distinctly different from all of the bisexual main sample clusters. Attempts to generalize from this clinical bisexual group to a larger population would be doomed to failure. This underscores the importance of recruiting nonclinical samples if one wants insight into the nature of bisexuality in the population at large. Our data empirically confirm many previous nonempirical warnings against clinical samples in studies of sexual orientation.

KEYWORDS:

• sexual orientation
• bisexuality
• cluster analysis
• Internet
• Klein Sexual Orientation Grid

Additional information

Notes on contributors

James D. Weinrich

James D. Weinrich, PhD, is currently the editor of the Journal of Bisexuality and former principal investigator of the Sexology Project at the HNRC (HIV Neurobehavioral Research Center). He collaborated with Fritz Klein on some innovative studies of bisexuality in the early years of the journal.

Fritz Klein

Fritz Klein, MD, was the founding editor of the Journal of Bisexuality. He passed away in 2006.

J. Allen McCutchan

J. Allen McCutchan, MD, was the principal investigator of the Medical Core of the HNRC at the time of the preparation of this article.

Igor Grant

Igor Grant, MD, is the founding principal investigator of the HNRC.

The HNRC Group

The HNRC GROUP is a research arm of the Department of Psychiatry at the School of Medicine at the University of California, San Diego (http://hnrc.hivresearch.ucsd.edu/). A great many individuals at the HNRC vitally contributed to aspects of this research.