A study published in the Journal of Veterinary Behavior in November–December 2025 showed that a single domestic cat learned to choose the non-matching object among three and to transfer this rule to new objects. In August 2026, the same researchers — Abu Bokor Siddik and Mst. Easmin Akter — published a follow-up to the work in Pet Behaviour Science, in which the cat successfully transferred the skill from visual stimuli to odors.
The classic "odd one out" task is simple in appearance: the animal is shown three objects, two of which are identical and one of which differs, and it must choose that one. However, many animals memorize specific objects rather than the rule. True proof of the concept is considered to be successful transfer to completely new stimuli, preferably on the first attempt. In the study, the cat was trained on several tasks simultaneously, gradually increasing their number within a session. According to the authors, this approach hinders simple rote learning and encourages the formation of a general rule.
In the transfer test with new objects, the cat performed successfully. In 2026, the researchers inserted new sets of odors into the training: the cat chose the "non-matching" odor in 90–100 % of cases. The authors note that simpler explanations, such as a general preference for the unusual, cannot yet be fully ruled out.
Previously, cats have shown mixed results in such tests. Studies from the 1960s, including a comparison of cats, raccoons, monkeys and chimpanzees, more often demonstrated success in primates. Even a single well-documented case is important: it suggests that previous failures may have been linked not so much to the limited abilities of cats as to the training methodology.
The authors connect the work to the study of cognitive aging. The capacity for abstract thinking can be impaired in Alzheimer's disease, and cats are increasingly regarded as a natural model of such decline. Older cats develop cognitive dysfunction syndrome, and individual studies show accumulation of amyloid-beta in their brains — a key marker of the disease in humans.
The study is a case report on a single animal, so it is too early to generalize to all cats. The results require replication in a larger number of animals by independent groups. Owners of older cats who notice changes in behavior should consult a veterinarian: many medical problems cause similar symptoms.
Even a single success shows that cats are capable of more complex thinking than was previously believed, and opens the way to more precise tests of cognitive abilities in domestic animals.
