Besides humans, which animals are then most intelligent?

According to Edward O. Wilson, a behavioral biologist, the ten most intelligent animals are the following:

1. Chimpanzee (two species)

2. Gorilla

3. Orangutan

4. Baboon (seven species, Including drill and mandrill)

5. Gibbon (seven species)

6. Monkey (many species, especially macaques, the patas, and the Celebes black ape)

7. Smaller toothed whale (several species, especially killer whale)

8. Dolphin (many of the approximately 80 species)

9. Elephant (two species)

10. Pigs

(The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)