The intellectual capabilities of dolphins have long fascinated scientists, raising intriguing scientific and ethical questions. At the annual meeting of the American Association for the Advancement of Science, experts discussed the ethical and policy implications of dolphin intelligence and whether dolphins should be regarded differently based on their cognitive abilities.
Researchers have been studying dolphin intelligence for over three decades and the consensus is clear: dolphins are highly intelligent creatures. According to Lori Marino, an expert in cetacean neuroanatomy, dolphins rank as the second most intelligent species on Earth, surpassed only by humans.
Marino’s argument is based on studies of the dolphin brain, which reveals that bottlenose dolphins have larger brains than humans and possess a brain-to-body-weight ratio greater than that of great apes. These marine mammals also have a complex neocortex, responsible for problem-solving, self-awareness, and other traits associated with human intelligence. Furthermore, researchers have discovered Von Economo neurons in dolphins, which are linked to emotions, social cognition, and theory of mind. Overall, dolphin brains exhibit remarkable similarities to human brains.
The cognitive abilities of dolphins further reinforce their intelligence. Diana Reiss, a cognitive psychologist, highlighted that dolphins possess social intelligence comparable to that of great apes. They can recognize themselves in a mirror, understand complex gestures from humans, and even learn to request toys through an underwater keyboard. Reiss emphasized that much of their learning resembles that of young children.
Given the striking similarities between dolphins and humans, the question arises: should we treat dolphins more like people? Marino argues that confining dolphins in captivity, such as in zoos and aquariums, is unethical, considering their natural behaviors and needs. In the wild, dolphins have a vast home range, while captivity limits them to an extremely small area. Reiss expressed concern over large-scale dolphin culling, pointing out the need to use scientific knowledge to influence international policy and ethical considerations.
Thomas White, a philosopher, took the discussion further, suggesting that dolphins may be considered “nonhuman persons.” He argued that dolphins possess the essential characteristics of personhood, including self-awareness, emotions, personalities, self-controlled behavior, and ethical treatment of others. While defining personhood is complex, White believes dolphins meet the criteria.
However, experts caution that the scientific understanding of dolphin intelligence is still limited. Jacopo Annese, a neuroanatomist, highlights that the case for dolphin intelligence is speculative due to the scarcity of data. Scientists have yet to fully comprehend the roots of intelligence in the human brain, let alone in dolphins.
As the debate continues, it is crucial to approach the subject with a balanced perspective. While dolphins exhibit remarkable cognitive abilities, further research is necessary to deepen our understanding of their intelligence. Exploring the ethical implications and treatment of dolphins should prompt us to reflect not only on their welfare but also on our treatment of fellow human beings.
