The National Association for Research and Therapy of Homosexuality concludes,
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It is often claimed that sexual orientation is an innate and normal variation of sexuality and therefore immutable or unchangeable aspect of a person's core self or identity. But, there is no conclusive evidence that female homosexuality is innate or solely genetic or biologically based. Most respected scientists agree that homosexuality is due to a combination of social, psychological, and biological factors.<ref>http://www.narth.com/docs/FemaleHomosexualDevelopment.pdf</ref>}}