General Knowledge - Biology - Discussion

Being that humans use 15% of there brain, dolphins use 20%. Hence, they are way smarter.

This question is ambiguous because whales is a non-specific scientific term, which typically means cetaceans. And dolphins are cetaceans, members of the toothed whale group or "Odontoceti", this is an arbitrary division of the cetacean mammals for this question - as both killer whales (dolphins) and beluga whales (whales) are highly intelligent mammals.

The dolphin's large brain is structured for awareness and emotion. In fact, dolphin brains are more structurally complex than humans. As Emory University dolphin expert Lori Marino told Discovery News, If human standards for intelligence are applied to non-human animals, however, dolphins come very close to our own brain aptitude levels.

Out of the 4 given, Dolphins are intelligent. But We humans are the most intelligent mammals I guess.

Its the dolphins. Humans use ten percent of their brains while dolphins use twenty. Which is why they use waves as a form of communication and detection.