Ibn al-Haytham IQ

Ibn al-Haytham, known in Europe as Alhazen, was born in Basra around 965. He moved to Cairo under the Fatimid caliph al-Hakim, reportedly after proposing to regulate the Nile. When he realised the plan was impossible, he is said to have feigned madness to escape punishment and lived under house arrest until the caliph died. In that period he wrote his Book of Optics. He died in Cairo around 1040.

No figure exists. LifeScore lists about 160 as an editorial marker, range 145 to 175. It rests on the Book of Optics, his mathematical work and a method of testing ideas by experiment that many historians see as an early form of the scientific method.

He showed that vision happens when light from objects enters the eye, rejecting the older idea that the eye emits rays. He combined geometry, experiments with light and knowledge of the eye's anatomy to build the first broadly correct theory of seeing.

Later biographers tell that he promised the caliph al-Hakim he could control the Nile floods, realised on site that he could not, and pretended to be mad to avoid punishment. The story may be embellished, but it is the traditional account of how he came to write the Optics.

Ibn al-Haytham tested. He framed a claim about light, built a setup to check it and varied one condition at a time. He also distrusted authority, including the Greek texts he admired, which is a rare and valuable kind of independent judgement.

What supports it

• The Book of Optics survives and was translated into Latin around 1200.
• His theory of vision was broadly correct and far ahead of rivals.
• Roger Bacon, Kepler and others drew on his work.

What it cannot prove

• Biographical details, including the madness story, come from later writers.
• Some of his explanations, such as parts of his account of refraction, were incomplete.
• An editorial marker is a comparison aid built from achievement, not a measurement, and two careful readers could place it ten points apart.

Ibn al-Haytham's IQ is represented here by a retrospective estimate of 160, not a verified test result. Ibn al-Haytham is best known for exceptional scepticism. The useful question is what the surviving evidence shows, not whether a precise modern score can be recovered.

Sceptical and rigorous. He questioned even Ptolemy and demanded that claims be checked against controlled observation.

The dominant archetype here is The Experimenter. This archetype shapes decision patterns: what feels natural, what creates friction, and what blind spots tend to emerge.

Estimated IQ is 160. This is a rough estimate based on documented accomplishments and contemporary accounts, not a literal measurement.

UNESCO made 2015 the International Year of Light partly to mark a thousand years since his Book of Optics.

Ibn al-Haytham's estimate of 160 falls in the profoundly gifted IQ range. Want your own number rather than Ibn's? Take the free IQ test or the quick IQ test. See what an IQ of 160 means, place it on the IQ chart or check how rare it is with the IQ rarity calculator.