Probably around 50 to 60, but talking about IQ for ancient humans like Homo habilis from two million years ago is a bit tricky since IQ tests, by definition, represent the current average of human intelligence in a particular culture at a particular time. However, for a fun comparison, based on their brain size and inferred cognitive abilities, Homo habilis might have had an IQ in the range of 50 to 60.

Chimpanzees seem pretty smart – how different were they from Homo habilis? Homo habilis was significantly more intelligent than modern chimpanzees, with a brain 43% larger and 55% smarter, they demonstrated advanced problem-solving capabilities and adaptability.

Although speculative, we assigned an IQ to Homo habilis using the Encephalization Quotient (EQ). Humans, with an average IQ of 100, have an EQ of about 7.6, while Homo habilis had a higher EQ than chimpanzees, estimated at about 3.65. Translating EQ-to-IQ, mostly for fun, we can assign Homo habilis an IQ between 50 and 60. Of course, this doesn’t imply they could ace a modern IQ test, but it’s a fascinating way to consider their potential intelligence. 

And this relates to our origin story. Homo habilis lived about two million years ago, likely had an IQ in the 50 to 60 range. At 50 is when modern humans start asking simple questions like “What is that?” and “Where are we going?” So, although it’s speculative, it is reasonable to guess that by around two million years ago is when our ancestors starting asking simple questions. Maybe.

Want to dive deeper into how scientists measure animal intelligence? Take the 30-minute deep dive: The Real Story Behind the Evolution of the Brain.