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Why Do Children Prefer to Save Dogs Over People?

A study raises new questions about how kids make ethical judgments.

Photos by Sonsedska, Richey-Schmitz and Kuzmina/123RF
Source: Photos by Sonsedska, Richey-Schmitz and Kuzmina/123RF

Children and adults think differently about animals. Take my grandson Ryland. One afternoon when he was 8-years-old, we logged onto my computer and played The Moral Machine Game. It was devised by researchers at MIT to discover universal ethical principles. (See Should Self-Driving Cars Spare People Over Pets? ) Players have to choose whether a self-driving car should be programmed, for example, to spare a child if it means the car will crash into two old men.

Some situations involve saving a person at the expense of a dog or a cat. Over 40 million people from 233 nations and territories have played the game. The researchers found that, worldwide, one of the strongest moral rules is, “Spare people over animals.” As Dr. Azmir Sharif, one of the game’s developers, told me in an e-mail, “Everyone prefers humans to a large degree.”

But Ryland almost always sent the car careening into a person to save the dog or cat. Huh? Is something wrong with my grandson? Or do most kids value the lives of animals over the lives of people?

According to a new study published in the journal Psychological Science , the answer is yes. The question is: Why?

The Shipwreck Study

The lead co-authors of the study were Matti Wilks from Yale University and Lucius Caviola from Harvard. Here is a recap of the study and the most important results. (You can read the details of the study in this excellent PT post by Joshua Rottman.)

The researchers wanted to know whether children and adults differed in how much they prioritize people over animals. Two hundred forty-three kids between the ages of 5 and 9 and 224 adults participated in the study. All of them were asked to imagine a situation in which two boats are sinking but they can only save the passengers in one of them. One boat contained either one dog, one pig, or one person and the other contained one, two, 10, or 100 dogs or pigs or people. Each comparison had three options—save the people, save the animals, or they could not decide.

The Results

The differences between the decisions of the children and the adults were stark. This graph shows the percentage of kids (green) and adults (red) who elected to sacrifice the dogs and save the people.

Graph by Hal Herzog
Source: Graph by Hal Herzog

In every scenario, most of the adults opted to save people over dogs or pigs—even if saving one person would cause 100 dogs to die. Not so with the kids. In every scenario, the children were more likely than adults to save dogs rather than humans. Indeed, a third of the kids would sacrifice a single person to save a single dog. Adults, on the other hand, were four times more likely than the kids to save the life of a person over 100 dogs.

Both the children and adults valued dogs more than pigs. But in every comparison, children were less likely than adults to save people over pigs.

Why Do Kids Value Dogs and Pigs Over People?

In his 1975 book Animal Liberation , Princeton University philosopher Peter Singer argued that the roots of human exploitation of animals lie in “speciesism.” He defined speciesism as “a prejudice or attitude of bias in favor of the interests of members of one’s own species and against those of members of other species.” Singer argued that speciesism is as illogical and morally repugnant as racism or sexism.

The researchers in the Shipwreck Study found that children are much less speciesist than adults. They offer two reasons why this is the case. The first is evolution. For most of human history, animals played major roles in people's lives, particularly the creatures that ate us and the ones we ate. Hence, our ancestors may have evolved psychological mechanisms that promoted thinking of other species as separate from humans.

The researchers, however, believe that socialization rather than evolution is the major influence in the development of speciesism. They suggest humans are not natural speciesists. Rather, the prejudice against animals is, like racism, a widespread but learned bias that tends to show up during adolescence.

I loved this study. I agree with the authors that the tendency for children to elevate the interests of animals over humans is partly a matter of socialization. But I think there is another reason why 5-year-olds think differently than grown-ups about the treatment of animals—their limited ability to think rationally.

The iPhone Camera Hypothesis: Adults Are Smarter Than Children

The fact is that children’s brains are not fully developed when they are five years old. Indeed, their ability to think abstractly jumps when they are around 11 or 12 years old (See Dumontheil, 2014 ). This is where Harvard’s Josuha Greene’s camera model of ethical judgments comes in.

Greene (with whom Caviola is doing a post-doc) compares our moral operating systems to a camera that comes with several modes. One of these is the cognitive equivalent of the point-and-shoot “auto-mode” app built into iPhones. This moral system is intuitive, it requires little in the way of knowledge, and it is largely emotional. I use the default no-brainer iPhone app for most of my photography, and it usually takes good pictures. Similarly, our moral system is on auto most of the time. And these moral intuitions usually steer us in the right direction—don’t steal, don’t have sex with relatives, etc.

But, I have also installed a fully manual photo app called ProCamera on my iPhone for complicated lighting situations. It requires much more thought and knowledge than the auto-mode app. In the right circumstances, however, the manual app takes much better photos.

I think Greene’s camera model applies to the results of the Shipwreck Study. One reason adults are three times more likely than children to save humans over dogs is that adults have the option of flipping into the deliberative, manual mode of moral thinking. Grownups can logically weigh the relative value of the lives of people and dogs in ways that kids can’t.

Is there evidence that the decision to elevate the status of humans over animals reflects rational thinking rather than socially acquired prejudices? Yes.

Animal Rights Philosophers Sometimes Value Humans Over Animals

Take, for example, the two most influential animal rights philosophers, Singer and the late Tom Regan. In his book The Case for Animal Rights , Regan laid out the rights-based (deontological) argument for animal protection. Regan, however, argued that if four normal humans and a dog are in a lifeboat that only has room for four, the dog goes overboard. He wrote, “Death for the dog is not comparable to the harm for any of the humans.” Indeed, he goes further and says , “It would not be wrong to cast a million dogs overboard to save the four human survivors, assuming the lifeboat case were otherwise the same."

In Animal Liberation , Singer made the harm/suffering (utilitarian) case for animal equality. Yet he has argued that the death of nearly 3,000 people on 9/11/01 was a greater tragedy than the death of the 10 million chickens slaughtered on 9/11. Singer says that, unlike the chickens, the humans who died that day had many loved ones who suffered from their loss of friends and family members. And he added that death is more tragic to “beings who have a high degree of self-awareness, and a vivid sense of their own existence over time.”

People Become More Speciesist When They Listen to Their Heads Rather Than Their Hearts

Experimental evidence also supports the idea that people are more likely to elevate human welfare over animal welfare when they think deliberatively rather than rely on their intuitions. It comes from a study by Lucius Caviola and Valerio Capraro. They asked adults to imagine a difficult situation in which they had to save either a human or a very bright chimpanzee. Subjects in the experiment’s “deliberative condition” were told to rely on logic and reason in making their decision (the manual-moral mode). The subjects in the “emotion condition” were told that relying on emotions often leads to good decisions and that they should let their feelings guide their choices (the auto-moral mode).

The researchers found that when their decisions were based on logic, people were more likely to value human lives over the lives of chimpanzees than when they were told to heed their moral intuitions. In a second study, subjects were asked how they would divvy up $100 between a charity for humans and a charity for animals. The subjects primed to rely on logic donated more money to the human charity than subjects primed to trust their intuition.

The Bottom Line

My experience playing the Moral Machine Game with Ryland and the innovative studies by Caviola and Wilks and their colleagues indicate that kids tend to give more moral weight to non-human animals than adults do. I agree that this difference is, in part, the result of socialization and arbitrary cultural norms. But I would add another factor into the mix: When it comes to difficult moral judgments, adults are usually more sophisticated thinkers than 5-to-9-year-olds.

As Matti Wilks reminded me, however, the fact that valuing human life over the lives of other species is justifiable under some conditions does not mean the way we usually treat animals is morally defensible. She wrote to me in an e-mail, "We can make a coherent moral case for prioritizing human lives over animal lives in many cases, but I would argue it is more difficult to rationally defend the degree that we prioritize humans over animals."

I agree!

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Post-Script: Ryland is now 10. This morning, I called him and asked what he would do in a shipwreck situation involving one person or one dog. He immediately said, “I would save the dog.” When I asked him why, he said, “Because there are more people than dogs on the earth.”


Wilks, M., Caviola, L., Kahane, G., & Bloom, P. (2021). Children prioritize humans over animals less than adults do. Psychological Science, 0956797620960398.

Caviola, L., & Capraro, V. (2020). Liking but devaluing animals: emotional and deliberative paths to speciesism. Social Psychological and Personality Science, 11(8), 1080-1088.

Greene, J. D. (2014). Beyond point-and-shoot morality: Why cognitive (neuro) science matters for ethics. Ethics, 124(4), 695-726.