Green Party MP Kevin Hague has questioned a study that highlights a link between childhood trauma and sexual identity.
An Otago University researcher who examined results from the New Zealand Mental Health Survey of nearly 13,000 people between 2003 and 2004, says those who had traumatic childhoods were less likely to be heterosexual.
However, Mr Hague says that finding is just one aspect of the research.
He says some people would like to believe same-sex attraction is a learned behaviour, but he does not believe that is what the research shows.
He says people prepared to disclose sensitive information to the interviewer about their sexual orientation would be more likely to disclose information about childhood trauma.
The study suggests people who were sexually abused or raped as children are three times more likely to identify as gay or bisexual.
Lead researcher Elisabeth Wells says 15% of those who had been raped or sexually abused as children identified as gay or bisexual. Of those who had not been sexually assaulted, 5% were homosexual or bisexual.
Ms Wells says there are numerous studies which suggest similar connections between adverse childhood events and sexual orientation.