How Smart are Dolphins?

How smart are dolphins?  Zoologist Lori Marino, psychology professor Diana Reiss, and ethics professor Thomas White think they are smart enough to be considered “non-human persons who qualify for moral standing as individuals.”  There is certainly a lot of evidence to support that claim.

Richard C. Connor points out that the complexity of dolphin relationships is second only to that of humans’; Jonathan Ball posits that “in certain areas of the brain concerned with “emotional control, objectivity, reality orientation, humor, logically consistent abstract thought and higher creativity” dolphins have an higher ratio of neural density [than humans]“; Cambridge Student Online assures us that dolphins can use tools and are thus cultural beings; it has been shown that dolphins have a sense of the future; and the US military thinks they are smart enough “to seek out underwater mines, attach explosives and eavesdropping devices on enemy ships and help divers recover lost weapons from the ocean floor.”

That is not to say that dolphin intelligence has not been called into question.  Geoff Weir, the Conservation Director at the Australian Dolphin Research Centre, for example thinks that much of a dolphin’s brain is used to process sound while Dr. Paul Manger feels that dolphins have large brains because they need to keep warm in cold water, not because they are terribly bright.

Given the stakes, it is understandable that there should be debate on the subject.  For, if dolphins were to be recognized as non-human persons would it still be permissible to use them as pets in amusement parks or to employ them for our own ends in our wars?