Our relationships with animals are complex. We treat some animals very kindly; we keep them as pets, give them names, and take them to the doctor when they are sick. Other animals, in contrast, seem not to deserve this privileged status; we eat them, trade them, experiment upon them, and use them as sources of entertainment, often to their harm.

Dogs are worth more than pigs, horses more than cows, cats more than rats. And, by far, the worthiest species of all is our own. Philosophers have referred to this phenomenon of discriminating individuals on the basis of their species membership as speciesism. Some have even argued that speciesism is a form of prejudice that is analogous to racism or sexism.

Whether speciesism actually exists and whether it is related to other forms of prejudice isn’t just a philosophical question. These are psychological hypotheses that can be explored and tested. Yet surprisingly, psychological researchers haven’t been very interested in speciesism, with  fewer than 30 scientific publications on the topic over the last 70 years.  This pales in comparison with the nearly 3,000 publications on the psychology of racism in the same time frame. This relative neglect is strange.  After all, animals are everywhere – from serving as pets to filling plates.

Together with Jim A.C. Everett and Nadira S. Faber, I recently conducted research to determine whether this potential prejudice against animals is real and, if so, whether it resembles prejudice against people, such as racism and sexism. To that end, we developed a Speciesism Scale that assesses the extent to which a person has speciesist views and studied the nature of speciesism. Our research showed that speciesism is indeed a distinct psychological construct that reflects the degree to which people discriminate individuals on the basis of their species membership.

Our research showed that philosophers were right when they drew an analogy between speciesism and other forms of prejudice. Speciesism correlates positively with racism, sexism, and homophobia, and it seems to be underpinned by the same socio-ideological beliefs. That is, people who are high in speciesism also tend to be more prejudiced toward groups of people. And, similar to racism and sexism, speciesism appears to be an expression of Social Dominance Orientation, the belief that weaker groups should be dominated by stronger groups.  In addition, people who score higher in speciesism tend to be lower in empathy and are less open-minded in their thinking style. Men are more likely to be speciesists than women, but  speciesism is independent of age and education.

Speciesism also manifests in people’s behavior. In our studies, people who score higher in speciesism are more willing to help human beings than to help animals, and they prejudicially favor “superior” animals over “inferior” animals. For example, when given the choice of donating to a charity that helps dogs or pigs, most people are more likely to help dogs than pigs. But this difference was greater than usual among those who scored high on our measure of speciesism. Similarly, the higher people score on speciesism, the more willing they are to invest time to help homeless people than to help establish basic rights for chimpanzees. Finally, speciesism is related to ethical vegetarianism. People who scored higher on speciesism tended to prefer a meat snack over a vegetarian snack.

Critics of speciesism as a concept sometimes argue that the reason we care less about animals than about people is not due to species membership per se, but rather due to animals not being intelligent or not being able to suffer as much as humans. Our research calls this objection into question.  It’s true that people perceive “inferior” animals to be less intelligent – and less able to suffer – than human beings or other “superior” animals. However, people’s beliefs about a specific animal’s level of intelligence or capability to suffer was only weakly related to how they treated the animals. 

By far, the best explanation of people’s behavior is speciesism itself. For example, even though people know that dogs and pigs are about equal in intelligence and possess about the same ability to suffer, people are still are much more likely to help dogs than pigs. And, when asked whether they would rather help a chimpanzee or a human being who has a severe mental disability, people reported being much more willing to help the human being than the chimpanzee – even if they believed that the chimpanzee was more intelligent and more capable of suffering than the person.  

What can we make of these findings? This research tells us that speciesism shows up in our attitudes, emotions, and behavior towards animals. And, speciesism seems to be analogous to other forms of prejudice. Thus, these insights into the psychology of speciesism could inform our thinking about how we want to treat animals. If we consider racism to be wrong, and we know that racism and speciesism are psychologically similar, this might make us question whether speciesism shouldn’t be considered wrong as well. Either way, we have only begun to understand the psychological aspects of speciesism. Hopefully, more researchers will help to explore this intriguing phenomenon in greater depth.

For Further Reading

Caviola, L., Everett, J. A. C., & Faber, N. S. (2019). The moral standing of animals: Towards a psychology of speciesism. Journal of Personality and Social Psychology, 116(6), 1011-1029.


Dhont, K., Hodson, G., & Leite, A. C. (2016). Common ideological roots of speciesism and generalized ethnic prejudice: The social dominance human–animal relations model (SD‐HARM). European Journal of Personality, 30(6), 507-522. https://doi.org/10.1002/per.2069 

Everett, J. A. C., Caviola, L., Savulescu, J., & Faber, N. S. (2019). Speciesism, generalized prejudice, and perceptions of prejudiced others. Group Processes and Intergroup Relations.

Loughnan, S., Bastian, B., & Haslam, N. (2014). The psychology of eating animals. Current Directions in Psychological Science, 23(2), 104-108. https://doi.org/10.1177/0963721414525781

Singer, P. (1975). Animal liberation. Random House.


This blog is an updated version of a blog originally posted at Oxford Practical Ethics. 

Lucius Caviola is a PhD student at the University of Oxford. He studies human morality, including the psychology of speciesism. http://luciuscaviola.com