In a 2006 article in Scientific American Mind entitled "Do Gays Have a Choice?," Dr. Epstein attempted to answer a troubling question with scientific objectivity. He argued that the terms "gay" and "straight" are problematic, because sexual orientation actually exists on a continuum, with most people feeling attracted to people of both sexes at some point.

His online test, the Epstein Sexual Orientation Inventory (ESOI), allows you to determine where you are on the Sexual Orientation Continuum, and it also reveals your "Sexual Orientation Range," which is an estimate of the degree of choice people have in expressing their sexual orientation.

To take the ESOI free of charge, click here. The test is now available in 12 languages, all of which are listed in the English version.

An article by Dr. Epstein and his colleagues summarizing their findings about sexual orientation with a sample of nearly 18,000 people in 48 countries can be downloaded here.

Image from the Jounal of HomosexualityPublished in the Journal of Homosexuality, the study may help ease the pain of people who have doubts about their sexual orientation.  It might also lower the volume on the rancorous political debate about whether people can "choose" their sexual orientation. It presents a new theory of sexual orientation - the "Fluid-Continuum Model" - which suggests that sexual orientation is best described by two values:  a number indicating where one's sexual orientation lies on the Sexual Orientation Continuum and a number indicating one's Sexual Orientation Range.
Major findings of the study:
1)  Sexual orientation is not properly described by two or three category labels; rather, as Kinsey asserted nearly a century ago, sexual orientation exists smoothly on a continuum.  It's more like height than eye color.  Forcing people to adopt simplistic labels causes many people great distress, because there is necessarily a disconnect between the label they adopt and their actual sexual behaviors, fantasies, and attractions.  The new study quantifies the disconnect, which is substantial, and it also confirms that the greater the disconnect, the more stress anxiety people feel about their sexual orientation.
2)  Few people - possibly even less than 10 percent of the population - are exclusively straight or gay throughout their lives.  Most people experience some degree of same-sex attraction at some point.  In a society that was completely free of sexual orientation stigma, most people would probably be bisexual, as Freud suggested a century ago.
3)  People differ not only in where their interests anchor on the Sexual Orientation Continuum - their "Mean Sexual Orientation" (MSO) - but also in their "Sexual Orientation Range" (SOR) - roughly, how much flexibility they have in expressing their sexual orientation.  Some people have a wide SOR, some a very narrow SOR.  This goes to the heart of the debate about how much "choice" people have in expressing sexual orientation - and about how far someone can go in altering his or her sexual orientation.  The new study quantifies SOR and shows how it differs by demographic category.
4)  Gender differences in sexual orientation are even greater than previously suspected.  On average, women are not only more gay then men (higher MSOs), and they also have much larger SORs than men.
5)  The Sexual Orientation Continuum looks about the same for people in the U.S. as it does for people in 47 other countries around the world (in aggregate).  Although it does not prove this, the finding is consistent with the idea that the continuum is genetically determined.

Dr. Epstein and his collaborators have recently completed a much larger study - the largest study of sexual orientation ever conducted, with more than 500,000 people in 170 countries - which confirms and extends the previous findings. More information about the new study will be released in 2017.