Are we underestimating the intelligence of fish?

We already know that all animals are sentient beings who deserve to be treated with respect and compassion. But what role does the animals’ intelligence play? What if we learned that certain animals were even more intelligent than we believed? Would this help ensure that they get the humane treatment to which they are entitled?

A report published earlier this month in PLOS Biology puts previously-held assumptions to the test by suggesting that fish may have even higher cognitive abilities than we previously realized.

The recent study subjected cleaner wrasse fish to what is known as a “mirror self-recognition test.” In this test, the behaviors of the fish were monitored before and after they were marked with a colored tag in the presence of a mirror.

In this study, the animals appeared to show signs of self-awareness, as they spent more time looking at their reflection after being marked and engaged in activities attempting to remove the mark. While humans easily pass this test, other animals, including chimpanzees, elephants, dolphins and birds, have also passed. Demonstrations of higher cognitive abilities in these non-human animals has been one factor in aiding NAVS and other animal advocates to argue against their exploitation in the name of science.

And while researchers questioned whether the results of this experiment truly indicate that fish are self-aware (or whether their tests for self-awareness should be revised), it is worth mentioning that for years it has been speculated that researchers have been underestimating animal intelligence by designing experiments that would work well for humans—but not so much for the animals being tested. Attempting to learn about animals from their perspective, not the one that works for humans, may reshape our fundamental understanding of them and make us appreciate them—and protect them—even more.

What if animals have higher cognitive abilities than we thought?  Would, or should, that change our opinions of whether they should be used as research tools in the lab?

As our recognition of animal intelligence grows, so too should the ethical responsibilities of scientists who test on animals. Researchers cannot ignore the growing body of evidence that animals are smart, sentient beings and continue to subject them to painful experiments.

Just because humans have historically relied on animal experiments does not mean we need to continue to do so. Please help NAVS support the development of more human-relevant, non-animal based methodologies that can reduce and possibly replace the use of animals in science by making a donation today.



Kohda, M. et al. “If a fish can pass the mark test, what are the implications for consciousness and self-awareness testing in animals.” PLOS Biology.  February 7, 2019.

“Fish appear to recognize themselves in the mirror,” Science Daily. February 7, 2019.

This entry was posted in News and tagged on February 18, 2019.
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