Robert Epstein, one of America's most distinguished research psychologists (follow on Twitter at The test has been empirically validated with a sample of more than 600,000 people in 219 countries and territories.Īlthough many people believe that everyone is either 'straight' (heterosexual) or 'gay' (homosexual), sexual orientation actually exists on a continuum. You are about to take the Epstein Sexual Orientation Inventory (ESOI), a test of sexual orientation designed by Dr.