DAVE Chatten says you wouldn't expect someone working a supermarket cash till to join Mensa - but that's what Teresa Fitzsimmons does, and she's a member.

The executive director of Mensa in Britain, Mr Chatten says 80 per cent of Mensa members are from an executive background - but Teresa's not, and she's perfectly happy with her job.

"Sure I get bored and my mind wanders off but when I clock off I don't take any worries home with me," she says. "I'm on flexi time and it is perfect because I am studying for an Open University degree."

Recent publicity about her IQ has prompted customers at the Douglas branch of Dunnes Stores in Cork to ask Teresa when she is going to become managing director but she laughs off the suggestion, saying: "If it was that easy I would have made sure to put it down in my cv!"

Teresa, now 39, left school at 16 without qualifications, married and had children. A few years ago, she was reading a book about intelligence testing and took a test at the back. The author advised readers that if they got a certain score they should do the Mensa IQ test.

"I just decided to prove myself that I had some sort of a brain " Teresa explains.

"You can either do the test or you can't. I didn't find it difficult. I got a very high score but it is not really the done thing to say what it was."

"I suppose knowing I have this level of intelligence makes me a little more secure in myself."

Back then, Teresa was living in the North and the secretary of Northern Ireland Mensa invited her to join. "I didn't realise it could be such a social organisation," she says.

Now Teresa is secretary of Munster Mensa. After her marriage broke up she met her new partner Tom Brown, also a Mensan, through the association.

"We like to get together for a drink or a chat," she says of her local Mensa. "I hosted an R is for Russia evening in my home recently; we ate Russian food, drank vodka and had a quiz on Russia. It was great fun.

"Some people sit the test and join because they like to boast about their intelligence but we don't really have a lot to offer them."