Encephalisation quotient

Encephalisation quotient is an empirical measure of the relative intelligence of a certain species. It refers to the difference between the expected amount of brain mass for a given animal and its mass and the actual amount of brain matter present. If correct, this should give an empirical ranking of organisms from 'dumbest' to 'smartest'. Since this type of ranking places humans unambigiously at the top in terms of braininess, it is considered to be a somewhat accurate measure. It also correlates well in other animal families as to who constitutes the smartest within its family, although humans are unique in having both the highest encephalisation quotient within the mammal and primate families, but also the highest encephalisation quutient of all living organisms. while for example octopi are only the 'smartest' within their respective family.