FISH PASS MIRROR TEST, BUT DOES IT MEAN THEY’RE SELF-AWARE?
NEW YORK Scientists report that a fish can pass a standard test of recognizing itself in a mirror — and they raise a question about what that means.
Does this decades-old test, designed to show self-awareness in animals, really do that?
Since the mirror test was introduced in 1970, scientists have found that relatively few animals can pass it. Most humans can by age 18 to 24 months, and so can chimps and orangutans, says the test’s inventor, evolutionary psychologist Gordon Gallup Jr. of Albany College in New York.
Passing the test suggests an animal can “become the object of its own attention,” and if it does, it should be able to use its own experience to infer what others know, want or intend to do, said Gallup, who did not participate in the fish study.
The new paper released Thursday by PLOS Biology subjected up to 10 fish to various parts of the test.
When four fish were injected with a tag that left a visible brown mark under their throats, three scraped that part of their bodies against a rock or the sandy bottom of the tank, as if trying to remove it.
In all, the researchers concluded that the fish had passed the test.
But Alex Jordan, who’s at the Max Planck Institute for Ornithology, says his fish could have succeeded without possessing true self-awareness. Gallup said he believes the experimental procedure was flawed, so the fish can’t really be said to have passed the test.