They're disease-ridden whackjobs! Some whackjobs are "born that way", some get that way.
See post #56
Are brains “gay”?
Summary:
Scientists have not been able to find clear structural differences between the brains of boys and girls at birth. At that stage of life their properties and functions overlap almost entirely. The same is true for behaviours rather than structures. Male and female behaviour—let alone homosexuality and heterosexuality —is not hard-wired into the brain at birth.
Maternal interactions influence the brain structure and future sexual orientation. This means early hormonal effects on the brain are far from inevitable. In fact, only one quarter of the brain is formed in a new-born child; the rest is developed through learning and experience (environmental input).
We can be confident that whatever male/female differences
exist in adult brains (and, more are constantly being found), they will have been largely shaped by learning and behaviour.
But what learning and experiences do to the brain is not set
in concrete either. Brain cells are replaced in roughly seven year cycles, meaning that new neuron pathways can be formed and old ones reshaped. Intensive exercise, training or imagination changes the brain microstructure.
We are not victims of our biology or the experiences which
shape the detail of our brain. Anatomy is not destiny; change is always possible. The brain is plastic and is in a constant state of change. Indeed the question is rather: what change is not possible?
We would not want to say that the structure of the brain you
were born with has no effect. It has. It can be profound. But that structure can also be profoundly changed, and we don’t yet know the limits.
http://www.mygenes.co.nz/PDFs/Ch8.pdf