The Leeds University academic at the centre of a racism row has defended his view that black people have a lower average IQ than white people.
Black pupils tend to under-achieve compared with other ethnic groups
Dr Frank Ellis, a Russian tutor, says data stretching back 100 years points to a "persistent deviation" in the average IQ of black and white people.
More than 500 students have signed a petition calling for him to be sacked.
Leeds University said his views were "abhorrent" but there was no evidence he had discriminated against students.
Dr Ellis has expressed support for the Bell Curve theory, examined in a book by Richard Hernnstein and Charles Murray, which concludes that ethnicity can play a part in IQ levels.
"I have read an enormous amount of literature on this subject and I find it extremely convincing," he told BBC Radio 5 Live.
He praised the work of scholars such as Hans Eysenck and Arthur Jensen who have come to similar conclusions.
Their opponents were worried about the implications for equal opportunities, he said.
He said these ideas do not preclude the existence of some black people of exceptional intelligence.
"But we have to accept, I believe, that there are these differences," he continued.
"The way to deal with this is not to treat people as groups, but to treat them as individuals."
'Dirty little secret'
Dr Ellis said the assumption that IQ tests are the most valid way of testing intelligence was the "dirty little secret" of psychology, because society as a whole did not accept this.
He said he became interested in the issue of censoring sensitive debates through his studies of the media under Soviet and post-Soviet regimes.
He added that labelling him a racist was "an attempt to close down any discussion" and an attack on his freedom of speech.
"These days a racist is anything you don't like - it's a hate word. I have no strong feelings towards black people either way."
He said he had never treated any black student in a different way to any white student, and he had "done absolutely nothing wrong".
Dr Munira Mirza, a tutor in multiculturalism and community relations at the University of Kent, told 5 Live she believed IQ differences could be explained by social and historical factors and did not exist for biological reasons.
But she said: "I don't agree with his views but do defend his right to express them. That is the lifeblood of the campus - people can express views and be held to account for them.
"He's not calling all black people stupid - that is a caricature.
"Academics and students are resorting to lazy, blame-game discussion and not engaging in the debate," she continued.
"I would rather disagree with him openly and explain why his theories do not stand up."
Leeds University Secretary Roger Gair said: "Dr Ellis has a right to his personal opinions, but he does not have the right to treat students or colleagues in a prejudicial or discriminatory manner.
"The university has no evidence yet that this has happened, but we will look carefully at any such evidence presented to us."
He said the university's values included mutual respect, diversity and equal opportunity, but its staff had "freedom within the law to question and test received wisdom, put forward new ideas, controversial and unpopular opinions without placing themselves in jeopardy of losing their jobs".
The university has not confirmed whether Dr Ellis will face any disciplinary action.