A four-year-old girl has been admitted into Mensa before she has even started school.
Heidi Hankins, from Winchester, has been accepted into the exclusive society after tests showed she had an IQ of around 159.
Most adults have an IQ of 100 and Heidi has now become one of only 90 children under 10 in the UK to join Mensa - the society for individuals with unusually high IQs.
The university lecturer, who specialises in measuring children's IQs, said her results were "off the scale" after he measured her intelligence "out of curiosity".
"I got her the complete set of the Oxford Reading Tree books when she was two, and she read through the whole set of 30 in about an hour," he told the local paper.
"It's what you would expect a seven-year-old to do."
Chief executive of British Mensa John Stevenage commented:
"Heidi’s parents correctly identified that she shows great potential.
"We wish them well, and are pleased that they have chosen to join the Mensa network for support, where we aim to provide a positive environment for younger members to develop."
Heidi, who still enjoys playing with her Barbie dolls, now joins the likes of Stephen Hawking and Carol Vorderman - although the child genius' IQ beats the Countdown presenter's by five points.
In 2011, three-year-old Saffron Pledger joined Mensa after her father, eight-times champion of Countdown Danny Pledger, found she had an IQ of 140.
In order to qualify to join Mensa, individuals have to attain a score within the upper 2% of the general population. The youngest ever member is recorded as being two-year-old Elise Tan Roberts from North London, who joined the society in 2009.