The BBC and Mensa have apologised after a spokesman for the society described anyone with an IQ of below 60 as a "carrot" live on air.
Mensa member Peter Baimbridge made the comments while being interviewed on BBC Breakfast, sparking complaints from viewers.
He was being asked about the effectiveness of IQ tests at judging intelligence.
"So most IQ tests will have Mr and Mrs Average scoring 100 and the higher you get, the brighter you are. And if your IQ is somewhere around 60 then you are probably a carrot," Mr Baimbridge said.
After the interview with presenters Louise Minchin and Charlie Stayt, some of the complaints were read out on air. The hosts then apologised at the end of the programme and read out a personal apology from Mr Baimbridge.
British Mensa apologised for the comment, which was "totally inappropriate and does not represent the society's official position or view". A statement on its website said Mr Baimbridge has subsequently apologised for the remark and stressed that no offence was intended.
One viewer, an employee of learning disability charity Mencap, said she was "shocked" and "disgusted" by the comments. Ciara Evans, who has a learning disability, urged Mr Baimbridge to "engage his brain before his mouth".
One of the complaints read out on air came from a Dr Sullivan who said: "As a clinical psychologist who has worked with many people who have an IQ below 60, I find these comments to be offensive and completely incorrect. Such comments perpetuate the stigma around an individual with learning difficulties."
A BBC spokeswoman said: "Clearly we do not condone the comments that were made in any way and sincerely apologise for the offence caused."
Ms Evans, a campaigns assistant with Mencap, said: "As a person with a learning disability, I am shocked that someone has described people like me as carrots. We can achieve a lot in life: I live independently, have a full-time job and I'm getting married next year."