Abstract
Author discusses with his opponent dr. Chvala how much homosexual orientation is formed by biological conditions or if we should also expect the significant psychological influence.
He lists genetical, neuroendocrinological, physiologico-anatomical and immunological hypothesis about the development of sexual orientation. He brings to a close that possible psychogennic factors from early childhood can be discovered in the future research.
Nevertheless according to the current knowledge biological determinants seems to be crucial.