Cats are wonderful for many reasons, including their purr. When they’re content (or sometimes when they’re anxious, or in pain, or in need of attention, or to self-soothe) they purr. It’s often claimed that cats purr to speed up healing of physical injuries.

It’s probably not true.

In a myriad of cat articles, healing effects are usually connected to the vibrational frequency of the purring, which is an immediate red flag for me that signals pseudoscience. The basic idea of “healing through vibrations” has floated around for more than 100 years; an inventor in 1920 created a vibrating “Rife machine” that crackpots claim cures everything from cancer to Lyme disease.