( CNN ) Researchers say Dr. Ben Carson may be a brain surgeon , but science shows he 's dead wrong about how sexual orientation works . Wednesday on CNN , Carson , a retired neurosurgeon and potential Republican presidential candidate , said he `` absolutely '' believes being gay is a choice . But scientists say decades of research overwhelmingly shows sexual preference is inborn , not a choice . `` It does n't seem to be the social environment , it does n't seem to be the parents or peers that make you gay , '' said Gerulf Rieger , a lecturer in the department of psychology at the University of Essex in England . `` It seems to be something that comes from within . '' `` Sexual orientation is biologically determined , '' added Cynthia Struckman-Johnson , a professor of psychology at the University of South Dakota . `` I do n't think any educated person aware of the research would argue differently . '' In a statement Wednesday , Carson apologized for what he said on CNN , and softened his words , saying the verdict is still out on whether people are born with their sexual preference . `` I do not pretend to know how every individual came to their sexual orientation , '' he added . While science is seldom definitive about anything , especially something as complicated as why we love who we love , researchers say the preponderance of the evidence shows sexual orientation is not chosen . They point to studies showing children are aware of their sexual orientation at a young age . Plus , genetic studies suggest homosexuality runs in families . Finally , researchers have found that the very structure of the brain -- specifically , regions of the hypothalamus -- differs in gay and heterosexual men . `` Ask a bunch of straight guys [ if they could switch to being gay ] and they would tell you , 'Are you kidding me ? '' Rieger said . `` So the other way around does n't work either . '' So what was Carson 's scientific support for his argument that being gay is a choice ? He pointed to prisons . `` A lot of people who go into prison go into prison straight - and when they come out , they 're gay . So , did something happen while they were in there ? Ask yourself that question , '' Carson told CNN 's Chris Cuomo . Experts on sexual activity in prisons challenged the very premise of Carson 's statement , calling it `` preposterous '' and `` appalling . '' `` To , in any way , suggest that a person would go in as a heterosexual and then somehow become a homosexual as a result , that 's simply preposterous . There 's no evidence to support that , '' said Robert Dumond , a mental health counselor who 's testified to the Department of Justice about rape in prison . Prisoners do engage in homosexual practices , but that does n't mean they 've gone from straight to gay , the experts said . Prisoners are often raped , they say , or coerced to engage in sex in exchange for protection from violent prisoners . `` They 're physically forced or forced through blackmail to engage in sex , '' Struckman-Johnson said . `` To have someone say this is chosen is just showing such great disregard for what we know about the world of sexual assault in prison . '' Opinion : Prison does n't make people 'come out ' gay . The prisoners who are perpetrating the rape are often either gay to begin with , or are heterosexual and rape to subjugate other prisoners . `` It 's more about power than sex , '' said Chris Hensley , a criminologist at the University of Tennessee who 's done extensive research on sexuality in prison . `` These men do n't see what they 're doing as homosexual , and they will leave their incarceration heterosexual . '' Other prisoners do willingly engage in homosexual activity , but the experts say it 's more of a way to release sexual tension and have some degree of intimacy . `` It does n't mean they would choose someone of the same gender in any other situation , '' Struckman-Johnson said . Critics of these studies point out other research they say indicates that orientation is a choice , namely studies that show sexual orientation can change over the course of a lifetime , and that `` socialization '' can alter orientation . Overall , the scientists with whom we spoke said they were shocked at Carson 's arguments . `` I 'm deeply saddened on multiple levels that someone in the 21st century would take this position , '' Dumond said . Jen Christensen contributed to this report .
in recent decades of research overwhelmingly shows sexual preference is inborn , not a choice . Dr. Ben Carson told reporters that being gay is a choice and pointed to prisoners who engage in straight and leave voluntarily . Prisoners do engage in homosexual practices , but that does n't mean they ' ve switched from straight to gay , but disagree .