found that the methylation pattern in nine regions of the genome appeared very closely linked to sexual orientation, with a resulting algorithm using the methylation pattern to predict the sexual orientation of a control group with almost 70% accuracy. Research into the causes of homosexuality plays a role in political and social debates and also raises concerns about genetic profiling and prenatal testing. Evolutionary perspectives Since homosexuality tends to lower reproductive success, and since there is considerable evidence that human sexual orientation is genetically influenced, it is unclear how it is maintained in the population at a relatively high frequency. There are many possible explanations, such as genes predisposing to homosexuality also conferring advantage in heterosexuals, a kin selection effect, social prestige, and more. A 2009 study also suggested a significant increase in fecundity in the females related to the homosexual people from the maternal line (but not in those related from the paternal one). Sexual orientation change efforts There are no studies of adequate scientific rigor that conclude that sexual orientation change efforts work to change a person's sexual orientation. Those efforts have been controversial due to tensions between the values held by some faith-based organizations, on the one hand, and those held by LGBT rights organizations and professional and scientific organizations and other faith-based organizations, on the other. The longstanding consensus of the behavioral and social sciences and the health and mental health professions is that homosexuality per se is a normal and positive variation of human sexual orientation, and therefore not a mental disorder. The American Psychological Association says that "most people experience little or no sense of choice about their sexual orientation". Some individuals and groups have promoted the idea of homosexuality as symptomatic of developmental defects or spiritual and moral failings and have argued that sexual orientation change efforts, including psychotherapy and religious efforts, could alter homosexual feelings and behaviors. Many of these individuals and groups appeared to be embedded within the larger context of conservative religious political movements that have supported the stigmatization of homosexuality on political or religious grounds. No major mental health professional organization has sanctioned efforts to change sexual orientation and virtually all of them have adopted policy statements cautioning the profession and the public about treatments that purport to change sexual orientation. These include the American Psychiatric Association, American Psychological Association, American Counseling Association, National Association of Social Workers in