Yes, many animals show a preference for one limb over the other, much like human handedness. But the pattern looks very different from ours. About 90% of humans are right-handed, a ratio that holds across every culture ever studied. No other species comes close to that level of population-wide agreement. In most animals, individuals develop their own preference, but the species as a whole splits roughly evenly between lefties and righties.
How Animal “Handedness” Differs From Ours
The key distinction is between individual preference and population-level bias. A single cat might always reach for a toy with her left paw. That’s individual lateralization, and it’s common across the animal kingdom. Population-level handedness, where an entire species leans one direction, is far rarer. Humans are the extreme case: 87 to 90% right-handed, with only about 3% showing no preference at all. Among the 37 non-human primate species examined in one large comparative study, only chimpanzees and gorillas showed a statistically significant rightward lean, and even then, the split was modest.
Great Apes: Our Closest Comparison
Chimpanzees are the best-studied case. In a dataset of over 1,000 chimps, roughly 50% were right-handed, 29% were left-handed, and about 21% had no clear preference. That’s a real rightward tilt, but nothing like the human ratio. Gorillas showed a similar pattern: about 54% right-handed, 22% left-handed, and 24% ambiguous. Bonobos also lean right. Orangutans, by contrast, show no population-level preference at all.
The type of task matters. Chimps and gorillas are most likely to show right-hand dominance during complex bimanual tasks, like holding a piece of food steady with one hand while peeling it with the other. Simpler reaching tasks produce weaker or no population bias. This parallels the human pattern, where handedness becomes most obvious during skilled, coordinated movements.
Some Monkeys Are Strongly Left-Handed
Interestingly, a couple of monkey species approach human-level consistency but in the opposite direction. Golden snub-nosed monkeys are about 71% left-handed with zero ambidextrous individuals. Brown spider monkeys are 72% left-handed. These are the closest any non-human primate gets to the lopsided ratio we see in people, just mirror-reversed.
Cats and Dogs Have Paw Preferences
A meta-analysis of paw preference studies found that 78% of cats and 68% of dogs consistently favor one paw over the other. But unlike humans, there’s no population-wide lean toward the right or left. Cats and dogs split roughly evenly between left-pawed and right-pawed individuals.
One intriguing finding: in cats, sex predicts paw preference. Female cats are more likely to be right-pawed, while males tend toward the left. This sex difference doesn’t show up in dogs.
Kangaroos Are Lefties
Bipedal marsupials are one of the few groups outside primates with a strong population-level hand preference. Eastern grey kangaroos and red kangaroos are predominantly left-handed when grooming their noses, picking leaves, or bending branches. Researchers noted a “remarkable consistency” across bipedal marsupial species in favoring the left hand.
Red-necked wallabies add a twist: they use their left forelimb for tasks requiring fine manipulation and their right for tasks demanding physical strength. So even within one species, the “dominant” hand can switch depending on what the animal is doing.
Parrots Pick a Favorite Foot
Parrots are among the few animals that rival humans in the strength of their limb preference. Most parrots strongly favor one foot for grasping food, and which foot they choose is driven by which eye they prefer to look with. Eye preference explained up to 99% of the variation in foot use across parrot species studied. In some species, nearly every individual in the population favors the same side, producing the kind of uniform bias that’s otherwise almost exclusive to humans and kangaroos.
Octopuses Prefer Their Front Arms
With eight arms to choose from, octopuses face a different version of the handedness question. When reaching into an enclosed space to find hidden objects, they strongly prefer their front arms over their back ones, choosing an anterior arm 75% of the time on their first attempt. However, they don’t favor a specific front arm: left and right were used equally.
During object manipulation, the pattern gets more interesting. Octopuses consistently underused two arms on their right side (the third and fourth right arms), creating a measurable bias toward both front arms and left arms overall. When using multiple arms in sequence, they most commonly recruited the nearest neighboring arm, suggesting efficiency rather than fixed preference drives their choices.
Elephants, Whales, and Other Surprises
Elephants develop a “master tusk” that they preferentially use for digging, stripping bark, and other tusk-heavy tasks. Over time, this dominant tusk wears down more than the other, making lateralization visible to the naked eye.
Blue whales show lateralized feeding behavior that shifts with context. When lunging for prey at depths below 70 meters, they predominantly roll clockwise (right-biased). At shallower depths, they tend to roll counterclockwise (left-biased). Rather than a fixed preference, their lateral bias adapts to the physical demands of feeding at different depths.
Even animals with much simpler nervous systems show lateral biases. Toads, chickens, and fish react faster to predators approaching from the left side, suggesting that the two halves of their brains handle threats differently.
Why Handedness Evolved
Having one side of the brain specialize in certain tasks appears to increase efficiency. When each hemisphere handles different jobs, the brain can process two things simultaneously rather than creating conflicting signals. A chicken scanning for food with one eye while watching for predators with the other is a classic example.
For individuals, a dominant limb means faster, more coordinated movements for practiced tasks. For species that show population-level handedness, the advantage may be partly social. In group-living animals, coordinating movements in the same direction can improve collective behavior, from schooling fish to foraging primates.
What remains genuinely unusual about humans is not that we have handedness, but how extreme it is. The 90/10 right-to-left ratio, consistent across all human populations, has no clear parallel in other primates. Only a handful of species, including parrots and kangaroos, approach that kind of uniformity, and they arrived at it through entirely separate evolutionary paths.