This paper introduces the Gender Complex theory, a novel framework that proposes a multifaceted understanding of same-sex attraction. The theory acknowledges the potential interplay between biological, experiential, and ancestral factors, including genetic predisposition, personal and ancestral gender trauma, social and cultural environment, and intergenerational transmission. This paper explores the core tenets of the theory, provides detailed explanations with examples, and discusses potential areas for further exploration. The Gender Complex theory aims to offer a more inclusive and nuanced understanding of same-sex attraction, moving beyond simplistic explanations and acknowledging the intricate web of factors that may contribute to this natural variation of human sexuality.