It's usually found when looking within mammals and is only a first approximation at best, but it seems to be a useful one at least: https://en.wikipedia.org/wi

It's usually found when looking within mammals and is only a first approximation at best, but it seems to be a useful one at least: https://en.wikipedia.org/wiki/Encephalization_quotient https://en.wikipedia.org/wiki/Encephalization_quotient