A new relationship with animals, nature and each other.

Are Dolphins ‘Persons’?

Dolphins and Us

Part One: The Smartest of Us All?

“So Long, and Thanks for All the Fish!”
The famous message they left us in the sci-fi movie.

Amazing Abilities of Dolphins
What one scientist learned about them. It’s amazing.

Dolphins or Humans: Who’s Smarter?
Here are some of the facts. You decide.

Dolphin Society and Culture
How they live, learn, play and use their amazing echolocation.

They’re Super-Brainy, Too
Neuroscientist shows us a dolphin brain.

More Fascinating Stuff

The Great Researcher
Prof. Lou Herman taught us most of what we know. (Check out the videos.)

A Society that Works
Dolphin society is more successful than ours.

Are Dolphins “Persons”
Author Tom White explains what a “person” is.

Life and Culture
Their lives, games and gatherings.

How Smart is a Dolphin?
The processing power of their brains is huge.

Experimenting on Dolphins
Should we still be doing it? “Please don’t ask me,” says scientist who does it.

My Visit to the Dolphins
“A beautiful creature with liquid eyes was gazing up at me as we motored along.”

Other Links & Videos

Mirror Self-Recognition Test
How we know that dolphins are self-aware.

David Attenborough on Surfing

Spinner Dolphins with Humans

A Dolphin “Stampede”

And Another One!

And Riding the Bow Wave

Playing with Bubble Rings

Dancing in Tahiti

The Herman Investigation
The results that ended his research.

The Minds of Whales
A scientific paper about the brains of cetaceans.

Next: Part 2: The Business of Dolphins

This is an excerpt from In Defense of Dolphins: The New Moral Frontier by Thomas I. White, Ph.D. (Oxford: Blackwell, 2007), reprinted with the author’s permission.


Dolphins don’t always fare well at the hands of humans.  Dolphins in the eastern tropical Pacific Ocean are daily harassed, sometimes injured and even die in connection with the human fishing industry.  Hundreds of captive dolphins are used for our entertainment and research.  Thousands are deliberately slaughtered each year in hunts in Japan, the Solomon Islands and the Faroe Islands. The fact that dolphins have sophisticated cognitive and affective abilities, however, implies that these cetaceans are a “who,” not a “what.”  And this means that there’s a serious question about whether human behavior towards dolphins is ethically justifiable.

The basic reason that humans expect other members of our own species to treat us in particular ways (to respect our dignity, for example) comes from the kind of consciousness that our brains produce.  We are self-conscious, unique individuals who are vulnerable to a wide range of physical and emotional pain and harm, and who have the power to reflect upon and choose our actions.  Because we can experience pain so intensely and because we value our ability to choose our own actions so deeply, we neither accept nor minimize it when other people hurt, coerce, threaten or manipulate us.  We object to such actions so strongly that we label them not just as “inconvenient” or “unpleasant,” but as “wrong.”  Ethics—our labeling actions as “right” or “wrong”—is grounded in the idea that the type of consciousness that we have gives us special capacities and vulnerabilities.  When we label something as “wrong,” then, we’re saying that it crosses the line with regard to not respecting some fundamental feature that makes us human.

Humans have traditionally assumed that we are the only beings on the planet with this type of consciousness—and, hence, this combination of capacities and vulnerabilities.  However, scientific research suggests that dolphins also have this kind of consciousness.  Two questions, then, loom as critical: “What kind of beings are dolphins?” and, “What does our answer to the first question tell us about the ethical character of how humans behave towards dolphins?”

Personhood: A Start

The easiest place to begin an inquiry into what kind of beings dolphins are is to ask whether dolphins are “nonhuman persons”?  Philosophers use the concept of “person” to refer to any being with certain advanced traits.  The point of using a concept like this is to avoid the danger of anthropocentric bias.

You might be surprised to encounter the question, “Are dolphins persons?”  It might not even make sense to you.  “Of course they aren’t people,” you might say, “they’re dolphins not humans.”  Yet despite the fact that many of us use “human” and “person” as synonyms in common parlance, the terms actually mean different things.  “Human” is a biological concept, denoting membership in Homo sapiens.  “Person,” however, is a philosophical concept, indicating a being with capacities of a particular sort.

Although philosophers debate the appropriate criteria for personhood, there is a rough consensus that a person is a being with a particular kind of sophisticated consciousness or inner world.  Persons are aware of the world of which they are a part, and they are aware of their experiences.  In particular, persons are aware of the fact that they are aware, that is, they have self-awareness.  And the presence of such a sophisticated consciousness is evident in the actions of such beings.

If we translate this general idea into a more specific list of criteria, we arrive at something like the following.

1. A person is alive.

2. A person is aware.

3. A person feels positive and negative sensations.

4. A person has emotions.

5. A person has a sense of self.

6. A person controls its own behavior.

7. A person recognizes other persons and treats them appropriately.

8. A person has a variety of sophisticated cognitive abilities.  It is capable of analytical, conceptual thought.  A person can learn, retain and recall information. It can solve complex problems with analytical thought. And a person can communicate in a way that suggests thought.

Let’s go down our list of criteria, then, and see how dolphins fare.

1. A person is alive

This one is easy.  Dolphins are animals, so they are alive.

2. A person is aware

Dolphins are certainly aware of their external environments.  Dolphins are universally placed high on the biological ladder, and the fact that they are aware of the external world and able to interact with it is apparent from the way that they handle the demands of living in the ocean and from the simple fact that they can be so easily trained.  When we get farther down the list, we’ll try to judge how complex a dolphin’s awareness is.  But there’s little doubt that their behavior suggests a significant level of awareness.

3. A person feels positive and negative sensations

Most nonhumans react to cuts, bruises and broken bones as we do—with behaviors that suggest these beings feel pain.  Dolphins, too, clearly act in ways that suggest they experience “positive and negative sensations.”

4. A person has emotions

Among scientists and dolphin trainers, there is also little doubt that dolphins have emotions.  But this is not surprising, since a growing number of humans seem willing to concede that many nonhuman species have some kind of emotional life.

We’ve seen evidence for the idea that dolphins have emotions at a variety of points in our earlier discussion.

  • The dolphin brain has a limbic system—the part of the brain that generates emotions.  We also saw that emotional information may play a bigger role in the dolphin brain than in the human brain.
  • Evidence for emotions in dolphins includes: Ronald Schusterman’s account of an episode in which a dolphin expressed aggressive feelings and Denise Herzing’s description of a grieving dolphin in the wild.  Dolphins also show fear of predators and can become despondent after the death of a calf or companion.
  • A variety of dolphin behaviors are understood by scientists to communicate anger or displeasure.

Perhaps the most interesting point about dolphin emotions is that the emotional traits of dolphins appear to combine into the equivalent of our “personalities,” what researcher Carol Howard calls “dolphinalities.”  Trainers see differences in curiosity, timidity, playfulness, aggression, speed of learning and patience.  Some captive dolphins enjoy swimming with humans more than others.  Some like learning new behaviors more than others.  Even mothers differ; some refuse to cut the apron strings, while others encourage their young to become independent.  Dolphins also seem to have what we call moods.  Captive dolphins can be eager to work some days, lackadaisical on others, and stubbornly uncooperative on still others.

5. A person has a sense of self

It‘s one thing to experience physical pleasure, pain and a variety of emotions.  But it’s quite another to be aware that one is having these experiences and to be able to reflect on them.  And so, we come to one of the most important requirements for personhood—self-awareness.  Can a dolphin look inside and say, “I”?

There are a variety of grounds for believing that dolphins have some concept of self.

  • Dolphins may have a unique whistle called a “signature whistle.”  They reportedly use these whistles to initiate interaction, to stay in contact with each other when separated from a distance, and to communicate information about themselves.
  • Dolphins can recognize reflections of themselves in mirrors as just that, reflections.  To date, only humans, all the other great apes and elephants have demonstrated this capability.  Other nonhumans—and human children before a certain age—ignore the image or mistake it for another animal or child.  For dolphins to join us in this group, they would clearly need the capacity to say the equivalent of, “The image in this surface is a representation of me.  It is not some other dolphin.”
  • Dolphins can do things that appear to require a sense of self.  Most importantly, in order to do the kind of problem-solving documented by John Gory and Stan Kuczaj, dolphins would probably have to be able to reflect on the contents of their consciousness—something that surely requires self-awareness.

6. A person controls its own behavior

By “self-controlled behavior” we mean actions that are generated from within the person, not by irresistible internal or external forces.  In the case of nonhumans, this means at least a noteworthy ability to act independently of instinct, biological drives or conditioning.  The capacity of a person to be the author of his or her own actions is important for two reasons.  First, it demonstrates that a being’s cognitive and affective states are sophisticated enough to control its actions.  In addition, such control leads us to hold a person responsible for what he or she does.

Do dolphins control their actions sufficiently that we can say they choose them?  Do they show any evidence of understanding and using a concept of responsibility?

Choice and control over behavior

There is evidence that suggests that dolphins control their behavior on a number of fronts.

  • Certain feeding strategies (the use of mud rings, hydroplaning and herding) appear to be the product of deliberation and choice.
  • Fascinating accounts of unusual events (such as Rachel Smolker’s lost tool kit being found by one of the Monkey Mia dolphins, and Wayne Grover’s encounter with dolphins who solicit his aid to remove a fishing hook from a baby) appear to result from deliberation and choice.
  • Most impressive from a scientific perspective is John Gory and Stan Kuczaj’s research on dolphins’ ability to solve problems.  There seems little question that the behavior or the two dolphins involved in this research resulted from thinking and choice.

Choice and responsibility

The ability of dolphins to choose their behavior is also suggested in the actions of a community of wild Atlantic spotted dolphins that has interacted with humans since about 1980 in the Bahamas.  The dolphins initiated this contact, which typically takes place in shallow waters (about 20 to 30 feet deep) approximately 50 miles offshore.  The dolphins appear to be motivated simply by a desire for social interaction—perhaps some combination of curiosity, socializing or recreation. (There’s no food involved, and spending time with humans doesn’t give them more protection from predators in their environment.)  These dolphin/human encounters can last from 5 minutes to 4 hours involving anywhere from 1 to 50 dolphins.  Given a dolphin’s superior speed and agility in the water, the dolphins obviously control the duration and character of these interactions.  Cetaceans are the only wild animals known to actively seek out contact with humans in the wild.  It’s difficult to imagine any other explanation for this behavior than conscious choice.

More interesting than the fact that these interactions give us more examples of choice, however, is an incident that raises the possibility that dolphins may both understand and utilize a concept of responsibility.  This community of spotted dolphins has not only sought out human interaction, but it has allowed humans to observe aspects of its culture.  Since 1985, marine scientist Denise Herzing has observed and recorded these interactions with the aid of a changing group of volunteer assistants.  (I have been part of this group since 1990.)  Over time, two distinctly different encounters have emerged. In the one, the dolphins desire a high degree of social interaction with the humans.  In the other, the humans are expected simply to watch, as the dolphins go on with aspects of their lives. To date, these dolphins have shown: hunting and feeding; sexual behavior; disputes and the resolution of disputes; adult dolphins teaching the young skills like fishing;  baby-sitting; disciplining the young; juvenile behavior; and both peaceful and aggressive interactions between different species of dolphins (spotteds and bottlenose).  In one of the “observing” encounters that I was part of, a mother dolphin was teaching its calf how to fish.  One of the human swimmers mistook this encounter as one in which interaction was appropriate, and her attempt to engage the calf distracted the youngster from its task at hand.  The mother then swam in front of Herzing, performed a tail-slap (a sign of displeasure or attention getting), gathered her calf from the swimmer and returned to teaching its offspring how to fish.

What is striking about this action is that the mother dolphin tail-slapped in front of Herzing, not the offending swimmer.  Given the context of this encounter and the history of Herzing’s interactions with the community, it is likely that the mother targeted Herzing, and not the swimmer, because the dolphin recognized Herzing from years of encounters as the individual who was dominant in the hierarchy of humans and held her “responsible” for the actions of the other swimmers.  Moreover, this is consistent with the way dolphins deal with each other because Herzing reports that this is exactly the way this signal is used when directed to a responsible party of a juvenile subgroup of dolphins. It is likely, then, that the mother dolphin’s message had something to do with her sense of Herzing’s responsibility for her group.

7. A person recognizes other persons and treats them appropriately.

Do dolphins act in ways that suggest not only that they have a sophisticated inner world, but that they can recognize it when they encounter this trait in others?  That is, do they recognize other persons and then respond appropriately?  Specifically, do dolphins act towards humans in ways that suggest that they recognize us as the type of beings whom we are?

We have two reasons to think that they do.  First, dolphins seek out contact with humans, and they do so apparently only for the social contact.  Second, they treat us appropriately, even generously.

Social interaction

Dolphins appear to be the only beings other than humans who will go out of their way to seek out social contact with another species. The community of wild Atlantic spotted dolphins that Denise Herzing studies is probably the best example of this.  These dolphins began seeking out human interaction since about 1980, and they have continued, with varied levels of interest and enthusiasm, to interact with members of Herzing’s research team and with passengers on dive boats.

The significant issue is why these encounters take place.  The interactions satisfy none of the dolphins’ basic survival needs.  They receive no food or protection.  The dolphins aren’t touched or rubbed by the humans.  There’s no sexual stimulation.  Moreover, the interactions themselves don’t seem to be that rich from the dolphins’ perspective.  Even the best human swimmers aren’t as fast or agile in the water, so we don’t represent a challenge for them to swim with.  As mentioned in the last chapter, these interactions occasionally consist of playing a kind of “seaweed keep away” with humans.  But it seems unlikely that humans are amusing or interesting enough as play-mates to sustain the dolphins’ long-term interest.  So the dolphins’ primary motivation in engaging in these encounters is most likely some kind of gratification that comes solely from social interaction with humans.  It’s certainly possible that they recognize us as beings who are similar to themselves—that is, “intelligent”—and they’re curious about us in the same way that we’re curious about them.

Appropriate treatment

The second reason to think that dolphins recognize us as persons is that they behave in ways that suggest that this recognition matters to them.  That is, they behave towards us in a way that’s similar to how we behave towards each other.

The most basic sign that we recognize someone else as a person is that we treat that individual as “some one,” not “some thing.”  We appreciate their intrinsic worth, and we act accordingly.  Surely, one sign that we recognize other persons and treat them appropriately is that we go out of our way to help them.

Observations of dolphin social behavior reveal that they engage in a fair amount of behavior that helps one another.  For example, they assist ailing dolphins for no apparent reward.  The dramatic story about two dolphins at the Dolphin Research Center helping a sick dolphin new to the facility suggests that they value one another’s life.  Dolphins also appear to limit the amount of aggression they use against each other.  Ken Norris even claimed that the dolphins he studied “have a sweetness of disposition that makes them sweeter than we are.”  On balance, dolphins treat each other pretty well—probably better than how humans treat each other.

In general, dolphins also treat humans well.  There are relatively few incidents of dolphins harming humans.  And in a number of those cases, there’s reason to believe that the humans involved had engaged in behavior that they did not realize was provocative.

However, the most intriguing aspect of how dolphins deal with humans is the fact that, for centuries, stories have been told about dolphins helping humans who have gotten in trouble in the ocean.  These tales range from dolphins helping sailors navigate through dangerous waters to supporting people who have fallen overboard.  During the 1998 South Caribbean Ocean Regatta, for example, a sailor fell into the ocean while moving forward on his boat to drop a sail.  Because the seas were so rough, the rest of the crew lost sight of him.  As boats in the race searched for a couple of hours, the swimmer found himself surrounded by a group of dolphins.  At the same time, one of the boats saw two dolphins swim towards it, swim away, and then repeat the pattern.  Even though the boat had searched the area that the dolphins were swimming towards, the crew felt that the dolphins were trying to tell them something.  They followed the dolphins and were led to the swimmer.

If dolphins recognize that we and they are both aware and intelligent, it wouldn’t be unreasonable that they might value our lives and well-being as they do their own.

8. A person has a variety of sophisticated cognitive abilities.  It is capable of analytical, conceptual thought.  A person can learn, retain and recall information. It can solve complex problems with analytical thought. And a person can communicate in a way that suggests thought.

To most humans, the most important criteria for personhood are intellectual.  Persons must be able to think analytically and conceptually.  Their behavior must demonstrate cognitive capacities.  They must be “intelligent.”

We have seen a great deal of evidence in this book to suggest that dolphins have significant cognitive abilities.

  • There is reason to think that the dolphin brain can support advanced cognitive and affective operations.  It has a large cerebral cortex and a substantial amount of associational neocortex.  Anatomical ratios that assess cognitive capacity place it second only to the human brain.
  • Dolphins appear to have not only consciousness, but self-consciousness.  Their performance on the pointing and gazing experiments suggest that they can also recognize other minds.
  • Research that uses television screens shows that dolphins understand representations of reality—something that requires conceptual thought.
  • The dolphins’ performance on John Gory and Stan Kuczaj’s experiments on problem solving is particularly impressive.  The dolphins demonstrated an array of cognitive skills needed to solve new and complex problems.  They were able to “create a novel and appropriate solution in advance of executing the solution.”  They could represent the causal structure of their environment.  And, perhaps most notable, the dolphins were able to operate in a foreign cognitive environment.
  • Karen Pryor provided further evidence about dolphins’ abilities in problem solving, innovative thinking, learning and cognitive flexibility.
  • Lou Herman’s research into whether dolphins can understand artificial languages is particularly striking.  He showed that the two dolphins he studied can understand and work with the basic elements of human language (vocabulary, grammar, syntax, complex sentences, etc.).  Herman’s research provides additional examples of a cetacean ability to think abstractly and to operate in a foreign cognitive environment.
  • On balance, however, the most significant evidence for higher-order abilities in dolphins comes from observations of dolphin social intelligence—that is, the way that dolphins use their large brains in their natural environment rather than in controlled experimental conditions.  Such observations include examples of tool use, social organization, cooperative fishing, political alliances, limited aggression, acoustic and nonacoustic communication and managing relationships.

Are dolphins persons?

Dolphins, then, do quite well at measuring up against a fairly traditional set of criteria for personhood—even without taking into account the distinctive features that emerge from the fact that they are aquatic mammals.  They seem to have all of the traits that philosophers traditionally require for persons.