A three-year-old girl with an IQ of 155 has become the youngest member of Mensa, the organisation for people of high intelligence.
Rhiannon Linington-Payne underwent a rigorous assessment by an independent psychologist and was judged to have an IQ at the top rating.
She attends a private nursery school and is due to join a class of five- year-olds in September. Her mother Margaret, a former primary school teacher from Shropshire, said she has the reading age of children twice her age.
"She has always been fascinated by books. She has her nose in them all the time and when she can't find someone to read to, she even reads to our dogs," she said.
Rhiannon's high mental ability became apparent from about nine months, by which time she was sitting in her high chair flicking through books, and obviously paying attention to what was in them.
"By 18 months she recognised the sounds of all the letters of the alphabet and could repeat them. And at two years she was already starting to read," said Mrs Linington-Payne, who runs a riding training centre in Cleobury Mortimer in Shropshire.
Mensa says Rhiannon's score puts her in the top 1 per cent of intelligent people in Britain.
Eileen Southan, a Mensa spokeswoman, said: "Rhiannon has the honour of being the youngest of our 40,000 UK members and we are delighted to welcome her.
"It's very unusual for someone her age to gain membership because the standard tests for children are only designed for those aged five or over."
Dr Peter Congdon of the Gifted Children Information Centre, who tested Rhiannon's IQ, said she had achieved the ceiling limit in the Stanford- Binet test used to gauge IQ. "Rhiannon can read sentences at an age when most three-year olds are just starting to recognise letter sounds. But as well as being able to read like a seven-year- old she can also count up into her hundreds."