Alexander Fleming IQ

Alexander Fleming was born on a farm in Ayrshire, Scotland, in 1881. A small inheritance let him study medicine at St Mary's Hospital in London, where he stayed for his whole career. He served in the First World War studying infected wounds, discovered lysozyme in 1921 and penicillin in 1928. Howard Florey and Ernst Chain later turned penicillin into a usable drug, and the three shared the 1945 Nobel Prize.

No figure exists. LifeScore lists about 140 as an editorial marker, range 125 to 155. It rests on a strong academic record and on two discoveries, lysozyme and penicillin, that came from noticing and following up unexpected observations.

In September 1928 he returned from holiday to find mould growing on a dish of staphylococcus bacteria in his lab. Around the mould the bacteria had died. He identified the mould as Penicillium and named the substance it produced penicillin.

No. He could not purify it in useful amounts. In 1939 to 1941 Howard Florey, Ernst Chain and colleagues at Oxford purified it and showed it cured infections. All three shared the 1945 Nobel Prize in Physiology or Medicine.

Fleming found it in 1928 but could not purify or produce enough of it, and he moved on to other work. Between 1939 and 1941 Howard Florey, Ernst Chain and Norman Heatley at Oxford worked out how to extract and test it, and wartime factories in the United States scaled up production. Fleming, Florey and Chain shared the 1945 Nobel Prize.

Fleming's strength was attention. Where another scientist might have thrown away a spoiled culture, he asked why the bacteria near the mould had died. Spotting the meaningful anomaly is a key part of practical intelligence.

What supports it

• He won top prizes at St Mary's Hospital Medical School.
• His 1929 paper on penicillin described its antibacterial effect.
• He shared the 1945 Nobel Prize.

What it cannot prove

• Turning penicillin into a medicine was largely the work of Florey, Chain and their team.
• Luck played a real part in the discovery.
• An editorial marker is a comparison aid built from achievement, not a measurement, and two careful readers could place it ten points apart.

Alexander Fleming's IQ is represented here by a retrospective estimate of 140, not a verified test result. Alexander Fleming is best known for exceptional observation. The useful question is what the surviving evidence shows, not whether a precise modern score can be recovered.

Quiet, observant and practical. A scientist who noticed odd results others would throw away.

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

Estimated IQ is 140. This is a rough estimate based on documented accomplishments and contemporary accounts, not a literal measurement.

He also painted pictures using bacteria of different colours as his paint.

Alexander Fleming's estimate of 140 falls in the genius level IQ range. Want your own number rather than Alexander's? Take the free IQ test or the quick IQ test. See what an IQ of 140 means, place it on the IQ chart or check how rare it is with the IQ rarity calculator.