Dog and Cat Body Language Myths

Dogs and cats communicate mostly through posture, and a lot of popular wisdom about their body language is half right at best. Reading the whole animal, not one signal in isolation, is what animal behaviorists recommend. Here are the most common beliefs and what the research actually shows.

"A wagging tail means a happy dog."

Not always. A wag means a dog is emotionally aroused, which can be excitement, uncertainty or tension. A loose, wide wag that moves the hips is usually friendly. A stiff, high tail wagging fast in short arcs can come before a snap. Italian researchers found in 2007 that dogs tended to wag more to their right when they saw their owner and more to the left when facing an unfamiliar, assertive dog, and later work showed other dogs react to the difference.

"A purring cat is a content cat."

Often, but not always. Cats purr when relaxed, but also when stressed, in pain, giving birth or close to death. Vets are used to cats purring on the exam table. Purring seems to work partly as self-soothing, so look at the rest of the cat: a relaxed purr comes with soft eyes and a loose body, while a stressed one may come with flattened ears and a tucked posture.

"Yawning means a dog is tired."

Sometimes it means they're uncomfortable. Yawning, lip licking, turning the head away and showing the whites of the eyes (sometimes called "whale eye") are common signs of stress in dogs. They often show up when a child hugs a dog, a moment that looks cute in photos and is a frequent cause of bites.

"A slow blink from a cat means trust."

True, and you can return it. In a 2020 study at the University of Sussex, cats were more likely to slow-blink back at people who slow-blinked at them, and more likely to approach a stranger who had done so. Narrowing your eyes and closing them slowly is a simple way to say you're not a threat.

"My dog looks guilty because he knows he did something wrong."

Probably not. In a 2009 experiment by cognitive scientist Alexandra Horowitz, dogs looked most "guilty" when their owners scolded them, whether or not they had actually eaten the forbidden treat. The look of lowered head, averted eyes and tucked tail is a response to the owner's displeasure, not evidence of a guilty conscience.

"A cat showing its belly wants a rub."

Usually not. A cat rolling over is showing trust and relaxation, but the belly is vulnerable, and many cats respond to a hand there with claws and teeth. Chin and cheek scratches are a safer bet.

Signals that are reliable

• A dog's whole body: loose and wiggly is relaxed; still and stiff means pay attention.
• A cat's tail held upright with a slight hook at the tip is a friendly greeting.
• Ears pinned flat back, in either species, usually signal fear or irritation.
• Any sudden change in an animal's usual behavior can be a sign of pain or illness and is worth a vet visit.