Male or female. The differences that distinguish the two genders are physiological, functional, and psychological. "Sex" can refer to the genitalia or to behaviors engaging genitalia, including procreation. Whether their intention is erotic, obscene, pornographic, or a means of exploring gender issues, art dealing with sexual content can be highly controversial (as works dealing with politics, religion, or criminality can also be), and may result in alienating viewers whose tastes are at variance from the artist's. Although behavioral standards have been changing over time (at various rates in various cultures) students, and others whose power is subject to more powerful authorities (whether respected or not), should understand potential consequences of making or exhibiting works with sexual content. This caution is not intended to justify the disapproval of those judging such works. Such issues are likely to be complicated, and must be studied on a case-by-case basis.