Jessica Casey: The Aberdare Girl Who Scored 162 on Mensa's Test

Biography

What happened

ITV News Wales published the story on 18 May 2021 under a headline of the kind these results always attract: the 13-year-old Aberdare girl with a higher IQ than Albert Einstein and Stephen Hawking. Rhondda Cynon Taf Council followed on 4 June with a press release through Aberdare Community School, and Newsweek carried a first-person piece the same year.

The comparison in the headline needs handling with care. Neither Einstein nor Hawking is known to have sat a modern IQ test; the figures attached to them in popular culture are estimates, not measurements. What the record shows is narrower and verifiable: on the Cattell III B paper, 162 is the highest score available, and Jessica reached it.

What the Cattell III B measures

British Mensa uses the Cattell III B as one of its supervised tests, and the coverage of Jessica's result makes the crucial point in passing: 162 is the maximum a child can score on it. That is why the figure appears so often in British stories about young Mensa members.

This matters for interpreting the result. British coverage of young Mensa members converges again and again on the same figure, 162, because it is the ceiling of the paper rather than a coincidence. A score at the ceiling means the test could not separate the candidate from anyone else who also reached the top, and a different instrument would produce a different number. It is a qualifying threshold, not a measurement of the limit of a child's ability.

Two in one family

The research record notes that her brother Harrison, then 15, had achieved the same score and was already a member of Mensa, and names their parents as Amy and Lee Casey. The family also said she had been reading at the age of one.

Siblings at the ceiling of the same paper is the detail that made the story travel beyond Wales. It is also the point at which the coverage typically outruns the evidence: the sources gathered here record the results and the reading, and say nothing about how either child was taught.

What Mensa membership does and does not mean

Mensa admits people who score at or above the 98th percentile on a supervised test. Membership confers access to the society and its activities; it is not an academic qualification, a scholarship or a prediction.

That distinction rarely survives the headlines, which is why these stories tend to be written in comparison with famous physicists rather than in percentiles. For the children involved, the practical consequence is a membership card, a local newspaper article and, occasionally, a national one.

What is documented, and what is not

Firmly established: the score of 162 on the Cattell III B in 2021 at 13, the coverage by ITV News Wales and Newsweek, the school press release, and her brother's identical score.

Not established here: her date of birth, her subjects, her later examination results, or anything since 2021. She was a child when the story ran, and this page carries nothing about her school timetable or her family beyond what the press published.

Achievement Timeline

Jessica Casey — every milestone on this page, in order.

2021

ITV News Wales reports her score of 16ITV News Wales reports her score of 162 on 18 May

2021

Rhondda Cynon Taf Council issues a preRhondda Cynon Taf Council issues a press release through Aberdare Community School on 4 June

2021

Newsweek publishes a first-person piecNewsweek publishes a first-person piece on the result

Historical Comparison

Person	Country	Milestone	Age / Stat
Lawson Lundberg	United States	Joining Mensa at 3	Age 3
Nishi Uggalle	United Kingdom	Winning Channel 4's Child Genius in 2019	Age 10
Jessica Casey	United Kingdom	Scoring the maximum 162 on Mensa's Cattell III B test	Age 13
David Camacho	Mexico	Selection for a Jr. NASA programme, 2024	—
Sharvin Jeyendran	Australia	A Mensa test put him at 168, and the headlines put him above Stephen Hawki	—

What is documented — and what is not

✓ Documented

She scored 162 on Mensa's Cattell III B test in 2021 at 13 (ITV News Wales)
Rhondda Cynon Taf Council publicised the result through Aberdare Community School in June 2021
Newsweek published a first-person piece on the result the same year
162 is the maximum score available to a child on that paper

? Unverified, disputed or wrong

No source read states her date of birth
The details about her brother, her parents and her early reading come from the research record rather than pages read in full
Nothing documents her studies or life after 2021

Questions people ask about Jessica Casey

What is Jessica Casey's IQ?

She scored 162 on Mensa's Cattell III B test in 2021, the maximum the paper produces for a child. It is a test result reported by ITV News Wales, not a fixed measurement.

How old was she?

Thirteen. No source read here gives her date of birth.

Is that higher than Einstein's IQ?

Neither Einstein nor Hawking is known to have taken a modern IQ test. The figures attached to them in popular culture are estimates rather than measurements.