Two-year-old Adam Kirby joins Mensa with IQ higher than both David Cameron and Barack Obama

The 29-month-old can spell 100 words, and knows most of the times tables up to 10

Barack Obama (left) and David Cameron (right) have both had their IQs surpassed by a two-year-old (Getty Images)

A two-year-old from south London with an IQ higher than David Cameron's has become the youngest member of British Mensa.

Adam Kirby, from Mitcham, is not even speaking in full sentences yet, but according to The Daily Mail the 29-month-old whizzkid can spell 100 words, knows most of the times tables up to 10, and has learned the periodic table.

After he scored 141 on the Stanford-Binet IQ test - higher than both Mr Cameron and US president Barack Obama - he was invited to join British Mensa, the society for people with outstandingly high IQs.

He is the youngest boy ever to do so, slightly older than the group's youngest ever member, Elise Tan-Roberts who joined Mensa aged two years and four months in 2009.

Adam's father, IT consultant Dean Kirby, said: "Adam’s abilities are outstanding and we’ve been actively developing his intelligence since he was 10 weeks old - but we’re certainly delighted for him.

"While most children are just learning to stand up or crawl Adam was reading books. His development was just mind-blowingly quick.

"We used to show him cards with the words 'hippopotamus' and 'rhinoceros' on them and he could identify the right animals most of the time."

Adam’s score of 141 - falling just four short of the ‘Genius’ category - puts him way above the average Brit’s IQ of 100.

Mr Kirby said he and his wife Kerry-Ann "are both bright, but Adam is significantly more advanced at his age than we were.

"He knows the planets of the solar system, dozens of pairs of words with opposite meanings - he has a great sense of humour and most importantly he is self-motivated, athletic, very happy and playful."

John Stevenage, British Mensa’s CEO, said: "The members of Mensa always welcome new additions as we aim to stimulate people in an intellectual and social environment.

"We look forward to Adam joining Mensa and expect him to have a very bright future."