Brain Quantity
If "intelligence" was simply determined by absolute brain size, there would be no difficulty in deciding which species was top (Table 1 ).

Table 1. Approximate brain weights and body weights of some mammals,
in order of brain weight.

Species Brain Weight Body Weight
(approx.) (approx.)
grams tonnes
sperm whale (male) 7,820 37.00
African elephant 7,500 5.00
fin whale 6,930 90.00
killer whale 5,620 6.00
bottlenose dolphin 1,600 0.17
human 1,500 0.07
cow 500 0.6