He eventually came up with a complicated scheme in which all animals had a certain degree
of encephalization, which increased in jumps of two (so humans were 1, apes were 1/4, cats and dogs were 1/8, etc.).
Comparative analysis
of encephalization in mammals reveals relaxed constraints on anthropoid primate and cetacean brain scaling.
Not exact matches
In support
of that claim, one widely cited study found that the ratio
of brain volume to body mass — commonly referred to as the
encephalization quotient, or EQ — was the same for Cro - Magnons as it is for us.
As you'd expect from the above data, the
encephalization quotient (a measure
of brain size compared to body size) for the Dmanisi hominids and the Turkana Boy is well below that
of modern humans (6.3):