diagnosis have focused on pubescents in Tanner stages 2 and 3 (centering on children who have begun to show signs of pubertal development of sex characteristics but are not at or near the end of this process), discussion of hebephilia has also concerned attraction to pubescents and adolescents in general, which has contributed to confusion among those who have debated the topic. The DSM-5's diagnostic criteria for pedophilia and the general medical literature define pedophilia as a disorder of primary or exclusive sexual interest in prepubescent children, thus excluding hebephilia from its definition of pedophilia. However, the DSM-5's age criteria extends to age 13. Although the ICD-10 diagnostic code for the definition of pedophilia includes a sexual preference for children of prepubertal or early pubertal age, the ICD-11 states that "pedophilic disorder is characterized by a sustained, focused, and intense pattern of sexual arousal—as manifested by persistent sexual thoughts, fantasies, urges, or behaviours—involving pre-pubertal children." Because of some inconsistencies in definitions and differences in the physical development of children and adolescents, there is overlap between pedophilia, hebephilia and ephebophilia. The term hebephilia was first used in 1955, in forensic work by Hammer and Glueck. Anthropologist and ethno-psychiatrist Paul K. Benedict used the term to distinguish pedophiles from sex offenders whose victims were adolescents. Karen Franklin, a California forensic psychologist, interpreted hebephilia to be a variation of ephebophilia, used by Magnus Hirschfeld in 1906 to describe homosexual attraction to males between puberty and their early twenties, who considered the condition normal and nonpathological. She said that, historically, adults being sexual with pubescents was considered distinct from other forms of criminal sexuality (such as rape), with wide variations within and across nations regarding what age was acceptable for adult–adolescent sexual contacts. Bernard Glueck Jr. conducted research on sex offenders at Sing Sing prison in the 1950s, using hebephilia as one of several classifications of subjects according to offense. In the 1960s, sexologist Kurt Freund used the term to distinguish between age preferences of heterosexual and homosexual men during penile plethysmograph assessments, continuing his work with Ray Blanchard at the Centre for Addiction and Mental Health (CAMH) after emigrating to Canada in 1968. After Freund's death in 1996, researchers at CAMH conducted research on neurological explanations of pedophilia, transsexuality, and homosexuality, and based on this research, hypothesized that hebephiles could also be distinguished on the basis of neurological and physiological measures. Although hebephilia