Two children, one ceiling score
The Mensa paper sat by younger candidates has a maximum of 162, and both Casey children reached it. Harrison did so at 12; Jessica did so two years later at 13, which ITV News Wales reported on 18 May 2021 under the standard headline comparing her with Einstein and Hawking.
Rhondda Cynon Taf Council publicised the story from Aberdare Community School in a press release on 4 June 2021. School and council announcements of this kind are a useful kind of source: they name the institution, they are dated, and they are issued with the family's agreement.
What the reported detail says
The council release records that Harrison's parents are Amy and Lee Casey, that he read newspapers at the age of one, and that his favourite subject is mathematics. Those are the family's own descriptions, published in an official release rather than reconstructed by a reporter.
The reading detail is the sort of claim that should be attributed rather than asserted, and it is attributed here: it comes from the council's release quoting the family, not from an independent assessment.
Why siblings matter to the story
Two children in one household at the ceiling of the same test is statistically striking, and it is the reason the Welsh coverage ran at all. Mensa admits the top two per cent of test-takers; reaching the paper's maximum is rarer still, and two siblings doing it consecutively is the kind of coincidence that makes a local newsroom pick up the phone.
It also means Harrison is usually covered alongside Jessica rather than on his own, which is why his own result, achieved two years earlier at 12, is the harder of the two to find in print. The sequence in the coverage runs backwards: the sister's score made the news, and the brother's earlier one was reported as context for it.
Where Harrison Casey is now
The record in these sources ends in mid-2021. No examination results, university place or later activity is documented, and none is assumed here.
He was a school pupil when the story ran and would be an adult now. A test score at 12 is a fact about one afternoon; it is not a career, and this page does not present it as one.
What is documented and what is not
Documented: a score of 162 on the Mensa test at 12, the maximum available for under-18 candidates; his sister Jessica matching the score at 13 two years later; the link to Aberdare Community School through the council's press release of June 2021; his parents' names; and his favourite subject.
Not documented here: his date of birth, his examination results, his plans, and anything after 2021. The birth year on this page is derived from the ages reported in the Welsh coverage and should be treated as approximate.
| 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 |
| Harrison Casey | United Kingdom | Scoring the maximum 162 on the Mensa test at 12 | Age 12 |
| 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
- Scored 162 on the Mensa test at 12, the maximum available for under-18 candidates
- His sister Jessica matched the score at 13 two years later (ITV News Wales, May 2021)
- Story publicised by Rhondda Cynon Taf Council via Aberdare Community School (June 2021)
- Parents named as Amy and Lee Casey; favourite subject mathematics
? Unverified, disputed or wrong
- Date of birth is not published; the birth year here is approximate
- The claim that he read newspapers at one is the family's account in a council release
- Nothing after 2021 is documented in these sources
Questions people ask about Harrison Casey
What is Harrison Casey's IQ?
He scored 162 on the Mensa test at 12, which is the maximum the paper allows for an under-18 candidate. It is a test score rather than a measured ceiling.
How old is Harrison Casey?
He was 12 when he sat the test, and the coverage that names him dates from 2021. No date of birth appears in these sources.
Did his sister take the same test?
Yes. Jessica Casey matched his score of 162 at 13, two years later.
Where are they from?
Aberdare in Wales. The story was publicised by Rhondda Cynon Taf Council through Aberdare Community School.
What is his favourite subject?
Mathematics, according to the council's press release.
Is Harrison Casey on Wikipedia?
No Wikipedia article is recorded for him. The council release and ITV News Wales report are the primary references.
Where is Harrison Casey now?
Nothing after 2021 is documented in the sources used here.
Quick quiz: how well do you know Harrison’s story?
What score did Harrison Casey achieve at 12?
Who matched his score two years later?
Which town are the Caseys from?
Sources
- Mensa (Aberdare Community School press release) — Rhondda Cynon Taf Council, 2021-06-04
- The 13-year-old Aberdare girl who has a higher IQ than Albert Einstein and Stephen Hawking — ITV News Wales, 2021-05-18
Checked by the Geniuses.club editorial team. Ages are given as of September 2026.
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