DOLPHINS: SECOND-SMARTEST ANIMALS?

When human measures for intelligence are applied to other species, dolphins come in just behind humans in brainpower, according to new research. Dolphins demonstrate skills and awareness previously thought to be present only in humans.

New MRI scans show that dolphin brains are four to five times larger for their body size when compared to another animal of similar size, according to Lori Marino, a senior lecturer in neuroscience and behavioral biology at Emory University, and one of the world's leading dolphin experts. Humans also possess an impressive brain-to-body ratio.


"If we use relative brain size as a metric of 'intelligence' then one would have to conclude that dolphins are second in intelligence to modern humans," said Marino, who performed several MRI scans on dolphin brains.

Marino will be presenting her findings at next month's American Association for the Advancement of Science meeting.

"Size isn't everything," she admitted, but she says at least two other lines of evidence support her claims about dolphin intelligence.

First, various features of the dolphin neocortex -- the part of the brain involved in higher-order thinking and processing of emotional information -- are "particularly expanded" in dolphins.

Second, behavioral studies conducted by Marino and other experts demonstrate that dolphins exhibit human-like skills. These include mirror self-recognition, cultural learning, comprehension of symbol-based communication systems, and an understanding of abstract concepts.

From Discovery News