Horse breed been produced. Such restrictions have led to legal challenges in the United States, sometime based on state law and sometimes based on antitrust laws. Horses can crossbreed with other equine species to produce hybrids. These hybrid types are not breeds, but they resemble breeds in that crosses between certain horse breeds and other equine species produce characteristic offspring. The most common hybrid is the mule, a cross between a "jack" (male donkey) and a mare. A related hybrid, the hinny, is a cross between a stallion and a jenny (female donkey). Most other hybrids involve the zebra (see Zebroid). With
Social groups in male and female prisons in the United States gangs, which are initially formed to provide protection to their members, as these members can no longer rely on norms or correctional officials to do the same. While homosexual contact is common in both male and female prisoners, female inmates tend to emphasize an emotional connection, sometimes displaying affection without any intention of sexual contact, male inmates tend not to display any affection despite frequent sexual interaction. This phenomenon is caused partially by the extreme stigmatization of homosexuality in male prison populations. Prison conditions encourage young male inmates to emphasize their masculinity, causing participants in homosexual relationships typically explain their