[huytersd]

They also had a lower brain to body ratio so weren't as intelligent.

[namlem]

Their ratio was about the same as homo sapiens. It's not clear that they were less intelligent, they seem to have had a similar degree of intelligence based on findings from caves in Spain.

[huytersd]

About the same but significantly lower. Neanderthal cave art is basically scribbles and scratches compared to say Altamira.

[bmer]

Why is brain:body ratio correlated with intelligence?

[huytersd]

It’s pretty much the one metric that holds true across all animal species. Read about EQ (encephalization quotient)