Working class people have lower IQs than those from wealthy backgrounds and should not expect to win places at top universities, an academic has claimed.
Newcastle University's Bruce Charlton said fewer working class students at elite universities was the "natural outcome" of class IQ differences.
The reader in evolutionary psychiatry questioned drives to get more poorer students into top universities.
The government has criticised Dr Charlton's comments.
Dr Charlton said: "The UK Government has spent a great deal of time and effort in asserting that universities, especially Oxford and Cambridge, are unfairly excluding people from low social-class backgrounds and privileging those from higher social classes.
"Yet in all this debate a simple and vital fact has been missed: higher social classes have a significantly higher average IQ than lower social classes."
The fact that so few students from poor families get into Oxbridge is not down to "prejudice" but "meritocracy", he said.
Higher Education Minister Bill Rammell said: "These arguments have a definite tone of 'people should know their place'.
"There are young people with talent, ability and the potential to benefit from higher education who do not currently do so. That should concern us all."
Sally Hunt, general secretary of the University and College Union, said: "It should come as little surprise that people who enjoy a more privileged upbringing have a better start in life.
"It is up to all of us to ensure that not having access to the social and educational benefits that money provides is not a barrier to achieving one's full potential."