Intelligent dolphins?

New research which suggests that dolphins are not intelligent has been dismissed by marine mammal experts as flawed.

According to Paul Manger, of the University of the Witwatersand in Johannesburg, the structure of the dolphin’s brain is not built for complex information processing, “but to counter the thermal challenges of being a mammal in water”, in other words it is an adaptation to life in cold water. 
 
Mark Simmonds, WDCS Director of Science, comments: ‘Manger is putting forward what he and everyone else who is interested in intelligence knows to be a new theory that contradicts what other experts are saying. There is no doubt that dolphins have unusual brain structure relative to terrestrial mammals and this reflects millennia of separate evolution. However, you cannot measure intelligence from brain size or anatomy. Whilst these aspects of anatomy give clues, such an approach is rather old-fashioned.
 
Intelligence is investigated by behavioural studies and there are now many careful scientific studies that have been published that help establish the case that these animals should be regarded as intelligent. The same kinds of tests that have helped to establish intelligence in the great apes have been applied successfully to dolphins. I have recently reviewed the relevant scientific literature (and have a scientific paper in press on cetacean intelligence) and I believe Manger to be incorrect in his interpretation of the available behavioural data.'

The process of science is one in which theories are published, reviewed and challenged by others and there is no doubt that this work will precipitate a strong response. Professor Lori Marino of Emory University in the US, an expert on dolphin behaviour and brain anatomy, said 'Manger flagrantly brushes aside decades of work by a whole generation of well-respected and internationally-known marine mammal scientists whose findings provide no support for his arguments. Moreover, Manger’s findings are based on a number of incorrect data values and flawed data analytic techniques.  In a paper we are preparing my colleagues and I will show that Manger’s findings on thermoregulation and brain size are an artifact of body size. Finally, Manger’s arguments rely upon outdated and stunningly obsolete views of dolphin brain structure. In sum, it is very unfortunate that such a methodologically and theoretically flawed paper as Manger’s has received any attention at all.'

There is considerable evidence from many scientists pointing to the fact that dolphins are highly intelligent mammals. Simmonds added "Some media reports have featured Manger’s work without appreciating that it is just one theory, against a whole body of work that points in the opposite direction."

Source: WDCS