Transsexualism is a conition in which a person identifies with a physical sex different from the one that they were born with or assigned in cases where ambiguity of the child's sex organs led to assigning them a physical sex. Transsexualism is considered a taboo subject in many parts of the world and has become more widely known in Western nations in the late 20th century due to the sexual revolution, but remains a highly controversial topic. Negativism and discrimination about transsexualism may stem from religious beliefs or cultural norms. However, many cultures around the world and throughout time have not only held a place for transsexuals within their societies but even culturally sanction them, e.g. the so-called two-spirit people in native American tribes.