A 12-YEAR-OLD girl has beaten great minds including Stephen Hawking and Albert Einstein to get the maximum Mensa IQ test score.

British schoolgirl Lydia Sebastian joined the 1 per cent of those who have sat the exam who have obtained the highest mark of 162, putting her in the top 99.9th percentile of the population.

Lydia, from Essex, described the fiendishly difficult intelligence test as “easy”, according to Cascade news agency. She completed the 150-question Cattell III B paper, which primarily measures verbal reasoning ability, during her school holidays.

“At first, I was really nervous but once I started, it was much easier than I expected it to be and then I relaxed,” she said. “I gave it my best shot.”

Her father, Arun Sebastian, a radiologist at Colchester general hospital, said his daughter had spent an entire year talking about the test and had researched IQ test websites herself. “When I heard she had the maximum possible mark, I was overwhelmed, and so was my wife,” he said.

Lydia, who is about to start year eight at Colchester County High school for girls, has read all seven Harry Potter books three times and played the violin since aged four.

An only child to Mr Sebastian and Erika Kottiath, an associate director at Barclays Bank, she started talking at just six months.

“At the time, I was a trainee doctor and my wife was studying chemistry and I was away at the weekends,” said her 43-year-old father. “She used to say a few words to me on the phone.

“She also had an early interest in reading. When she was a few years old she was reading books that were for children several years older than her.

“We really have done nothing special with her.”

Lydia, whose favourite subjects include maths and physics, is now applying to join the Mensa society. Her parents, both originally from Kerala in southern India, say she voluntarily does homework until 8.30pm or 9pm.

“We’ve got a fairly laid-back view [about education],” added Mr Sebastian. “If a child is pushed to do something that’s not designed for their age then, personally, I’d feel they they’d be missing out on other things.”

Amazingly, Lydia is not the first child genius to achieve a perfect Mensa score this year, joining Nicole Barr, a 12-year-old also from Essex, as well as Aahil Jouher, a 10-year-old from Blackburn.

Hit reality show Child Geniuson the UK’s Channel 4 this year featured Holly, an 11-year-old who can recite pi to 122 decimal places, and 12-year-old Thomas, from Leeds, who sprints up and down the garden while spelling words like “hexamethylene”.

Child Genius UK's Channel Four is entering the final stages of its Child Genius competition which is seeking to discover the smartest child in Britain. Courtesy: Channel Four

But the TV competition also caused controversy among viewers concerned about these over-achieving kids missing out on their childhood. David, 11, said on the series that winning was his “destiny”, and his parents used Chinese medicine techniques such as cupping to give their son the edge. Giovanni, 12, was driven by super-competitive father Mattheo, who once participated in the Chemistry Olympics, and said: “You need to push them to the limit, with their body and with their brains. If there is something in Giovanni, it will be developed, I will make sure of it.”

Producers from the show said the children were all assessed by psychologists and took pride in their intelligence. “Knowledge is something that should be applauded, not something to be ashamed of,” said producer Anna Strickland. “It’s something we should celebrate. So it’s great for the children to be in an environment where that is the case, and to be among other children who are similar to them.”

British Mensa’s Gifted Child Consultant Lyn Kendall said children with extraordinary abilities often exhibit traits including unusually good memory, passing intellectual milestones and reading early, awareness of world affairs and asking lots of questions. They can also be musical, talkative and intolerant of other children.

She says most child geniuses appear to succeed through a combination of nature and nurture.

Joanne Ruthsatz, a gifted children researcher from Ohio State University, told Ozy that child prodigies are as rare as 1 in 5000-10,000. She believes kids with preternaturally advanced abilities may store memories in their cerebellums, where most of us store our motor memories.

Scientists think there may be a prodigy gene or mutation that assists with a few specific skill sets including memory and extreme attention to detail.

David Feldman, professor of child development at Tufts University, warned that there is a difference between “prodigy” and “extraordinarily gifted”. He said that even a child like Laetitia Hahn, an 11-year-old from Germany who speaks five languages, would probably not qualify, unless she was speaking those languages like an adult linguist.

Child geniuses can face hardships, struggling to make friends and encountering existential questions at an early age. All parents can really do is let nature take its course.