Emory University neuroscientist Lori Marino spoke about dolphin intelligence at the American Association for the Advancement of Science conference (AAAS) in San Diego, on Feb. 21, 2010.
"Many modern dolphin brains are significantly larger than our own and second in mass to the human brain when corrected for body size," Marino says.
Some dolphin brains have features related with complex intelligence in other mammals including a large expanse of neocortical volume that is more convoluted than our own.
"Dolphins are sophisticated, self-aware, highly intelligent beings with individual personalities, autonomy and an inner life. They are vulnerable to tremendous suffering and psychological trauma," Marino says.
This raises lots of questions for the aquarium industry where dolphins are kept for entertainment and educational purposes.
"Our current knowledge of dolphin brain complexity and intelligence suggests that these practices are potentially psychologically harmful to dolphins and present a misinformed picture of their natural intellectual capacities," Marino says.
Marino worked on a 2001 study that showed that dolphins can recognize themselves in a mirror -- a finding that indicates self-awareness similar to that seen in higher primates and elephants.