The Ethical Implications of Dolphin Intelligence: Dolphins as Nonhuman Persons

One of the most important aspects of science is that scientific progress regularly raises important ethical questions.  As scientific research produces a more accurate picture of the universe, it often reveals ways that human attitudes and behavior may be out of synch with these new facts. For example, human slavery and dissimilar treatment between men and women became ethically indefensible when scientific research proved that claims about racial and sexual superiority were nothing more than irrational biases.

In the world of marine mammal science, a similar phenomenon has been occurring. Over the last few decades, numerous scientific studies have found that cetaceans are far more intellectually and emotionally sophisticated than previously thought. Evidence is also growing that culture is important for at least some cetacean species.

Two important ethical implications follow from the present state of cetacean research.

First, the evidence for cognitive and affective sophistication—currently most strongly documented in dolphins—supports the claim that these cetaceans are “non-human persons, “ should be seen as “beyond use” by humans and have “moral standing” as individuals.  It is, therefore, ethically indefensible to kill, injure or keep these beings captive for human purposes.

At the same time, because so much of the discussion of cetacean intelligence focuses on ways that cetacean cognitive abilities are similar to those of humans, there is the risk that researchers will fail to recognize and appreciate critical differences—despite the fact that these differences reveal a great deal about cetacean intelligence. For example, the evidence for the centrality of “social intelligence” in the life of cetaceans underscores the challenge of identifying and assessing intelligence in nonhumans in a way that is free from the ethically indefensible factor of species bias. In order to survive in the oceans, large-brained mammals need to use skills that differ from those favored by their land-based cousins. What we may call a “technical intelligence” increases the odds of survival by handed hominids on land, but “social intelligence” (the ability to manage the nuances of close relationships with conspecifics, work cooperatively with them, earn their trust and receive their assistance and protection) is likely more important in the ocean. Accordingly, scientific research on cetacean intelligence must take great care not to inadvertently use only human criteria, lest unintended species bias color the outcome of otherwise rigorous scientific inquiry.