What does evidence-based research say about the development of sexual orientation in young and middle adulthood?

What does evidence-based research say about the development of sexual orientation in young and middle adulthood? Though the body of literature addressing sexual orientation, including heterosexuality, homosexuality, and bisexuality, is far from complete, the literature continues to grow. Your awareness of this literature helps inform your social work practice as you address the needs of clients with a variety of sexual orientations.