Elephant cognition is the study of animal cognition as present in elephants. Most contemporary ethologists view the elephant as one of the world's most intelligent animals. With a mass of just over 11 lb (5 kg), an elephant's brain has more mass than that of any other land animal, and although the largest whales have body masses twenty times those of a typical elephant, a whale's brain is barely twice the mass of an elephant's brain. In addition, elephants have a total of 300 billion neurons. Elephant brains are similar to humans' and many other mammals' in terms of general connectivity and functional areas, with several unique structural differences. The elephant cortex has as many neurons as a human brain, suggesting convergent evolution.