It's long been suspected that those most opposed to homosexuality may have such tendencies themselves - perhaps even without knowing it - but now a study suggests that this may be a fact.

Intense feelings of opposition to sexual orientation calls for self-reflection, says Richard Ryan Professor of psychology at the University of Rochester. He thinks that extreme opposition could be learnt from parents who are homophobic too.

Whatever the reason, Ryan believes that such phobias can have dire consequences for those who carry them. He explained to LiveScience that people who feel threatened by other people's sexual orientation might fear their own impulses or have been oppressed in the past by others who display homophobia such as their parents or siblings.

"We can have some compassion for them too, they may be unaccepting of others because they cannot be accepting of themselves."

While the idea that homophobes might struggle with homosexual tendencies is a compelling idea, Ryan says it's only one aspect of what makes people homophobic.

In four studies based on groups from Germany and the United States, researchers compared what people said (their overt view) and what they felt (or their implicit view) about homosexuality based on an interview and later, a reaction time test.

For the reaction test, participants had to categorise images of couples using the words "straight" and "gay". Still based in the reaction test, researchers also looked at participants' implicit orientation based on how quickly they reacted to questions around "me" and "gay" and "me" and "straight".

Furthermore, questionnaires aimed at learning more about the attitude and behaviour of parents towards homosexuality during participants' upbringing were filled out based on whether or not participants agreed with certain statements such as "I felt free to be who I am" or "My dad avoids gay men whenever possible".

Those participants who had more accepting parents showed more comfort in their implicit sexual orientation, while those whose parents displayed a more controlling and negative attitude were more likely to show a larger difference between their implicit sexuality and what they told researchers during interviews.

Researchers found that those participants who identified themselves as heterosexual in spite of displaying same-sex tendencies during the reaction test showed the most hostility towards homosexuality.

Ryan and lead author Netta Weinstein hope that their findings help to make sense of hate crimes such as gay bashing.

"We laugh at or make fun of such blatant hypocrisy, but in a real way, these people may often themselves be victims of repression and experience exaggerated feelings of threat," Ryan told LiveScience.