Sexual orientation is forms of sexual attraction to people. There are many different groups. Some examples are: attraction to a different gender (heterosexuality), attraction to the same gender (homosexuality), attraction to more than one gender (bisexuality),[1][2][3] and no attraction any gender (asexuality).[4][5]
The groups are part of sexual identity.[3] Some people use something such as pansexual or polysexual.[3][6] Other people use nothing at all. Androphilia and gynephilia are an alternative to the gender binary in homosexual and heterosexual. Androphilia is attraction to a man or masculinity (any quality or behavior linked to a man). Gynephilia is attraction to a woman or femininity.[7]Sexual preference overlaps with sexual orientation but is different.[8] A bisexual person may like one gender more than another.[9]Sexual preference may also give the idea of a degree of choice.[8][10][11] The scientific consensus (position in the community of scientists) is that sexual orientation is not a choice.[12][13][14]
Scientists do not know the exact cause of sexual orientation. There is some evidence of genes involved, however the main theory is related to hormones when a baby is growing inside the mother.[15] For males, there is better proof of a biological cause of sexual orientation than social causes.[15][16][17] In women, there is some evidence that social factors may play a small role.[15]