A proportion of victims of rape or other sexual violence incidents are male. Historically, rape was thought to be, and defined as, a crime committed solely against females. This belief is still held in some parts of the world, but rape of males is now commonly criminalized and has been subject to more discussion than in the past. Rape of males is still taboo, and has a negative connotation among heterosexual and homosexual men. Community and service providers often react differently to male victims based on their sexual orientation and the gender of their perpetrators. It may be difficult for male victims to report a sexual assault they experienced, especially in a society with a strong masculine custom. They might be afraid that people will doubt their sexual orientation and label them homosexual, especially if raped by a male, or that they may be seen as un-masculine because they were a victim, and therefore many statistics underestimate how many males are raped due to their unwillingness to report sexual assault and rape. Most of the time, male victims try to hide and deny their victimization, similar to female victims, unless they have serious physical injuries. Eventually, the male victims may be very vague in explaining their injuries when they are seeking medical or mental health services. Research and statistics General Research about male-victim rape had only just begun to appear by 1980, focusing mostly on male children. The studies of sexual assault in correctional facilities focusing specifically on the consequences of this kind of rape were available in the early 1980s, but nothing was available during the previous years. Most of the literature regarding rape and sexual assault focuses on female victims. Only recently have some other forms of sexual violence against men been considered. In the 2010–2012 National Intimate Partner and Sexual Violence Survey (and a prior edition of this study completed in 2010), the Centers for Disease Control (CDC) measured a category of sexual violence called "being made to penetrate" which captures instances in which victims were forced to or attempt to sexually penetrate someone (of either sex), either by physical force or coercion, or when the victim was intoxicated or otherwise unable to consent. The CDC found in the 2012 data that 1.715 million (up from 1.267 million in 2010) reported being "made to penetrate" another person in the preceding 12 months, similar to the 1.473 million