as females come to identify as male later in life. Scientists speculate that the definition of masculine characteristics during puberty and the increased social status afforded to men are two possible motivations for a female-to-male transition. Psychological Psychiatrist and sexologist David Oliver Cauldwell argued in 1947 that transsexuality was caused by multiple factors. He believed that small boys tend to admire their mothers to such a degree that they end up wanting to be like them. However, he believed that boys would lose this desire as long as his parents set limits when raising him, or he had the right genetic predispositions or a normal sexuality. In 1966, Harry Benjamin considered the causes of transsexuality to be poorly understood, and argued that researchers were biased towards considering psychological causes over biological causes. According to the DSM-5, gender dysphoria in those assigned male at birth tends to follow one of two broad trajectories: early-onset or late-onset. Early-onset gender dysphoria is behaviorally visible in childhood. Sometimes gender dysphoria will stop for a while in this group, and they will identify as gay or homosexual for a period of time, followed by recurrence of gender dysphoria. This group is usually androphilic in adulthood. Late-onset gender dysphoria does not include visible signs in early childhood, but some report having had wishes to be the opposite sex in childhood that they did not report to others. Trans women who experience late-onset gender dysphoria are more likely be attracted to women and may identify as lesbians or bisexual. It is common for people assigned male at birth who have late-onset gender dysphoria to experience sexual excitement from cross-dressing. In those assigned female at birth, early-onset gender dysphoria is the most common course. This group is usually sexually attracted to women. Trans men who experience late-onset gender dysphoria will usually be sexually attracted to men and may identify as gay. Blanchard's typology In the 1980s and 1990s, sexologist Ray Blanchard developed a taxonomy of male-to-female transsexualism built upon the work of his colleague Kurt Freund, which argues that trans women have one of two primary causes of gender dysphoria. Blanchard theorized that "homosexual transsexuals" (a taxonomic category referring to trans women attracted to men) are attracted to men and develop gender dysphoria typically during childhood, and characterizes them as displaying overt and obvious femininity since childhood; he characterizes "non-homosexual transsexuals" (trans women who are sexually attracted to