A Trusted Friend in a Complicated World

12 Surprising Ways Orangutans and Humans Are Alike

Updated on Jul. 18, 2025

You'll be surprised by the traits we share with these shaggy red-haired great apes, our closest relatives in the world

The orangutan and human, an unlikely pair

One may live in rainforests and swing through the trees, while the other nestles into 500-thread-count sheets just to take a nap. But the orangutan and human have a lot more in common than you might expect. Researchers have discovered some head-tilting, smile-worthy similarities that just might shift the way we see our species.

Did you know we share nearly 97% of our DNA with orangutans? They might even be our closest relatives! (Move over, chimps.)

Reader’s Digest put together a dozen other fascinating facts about orangutans and humans to show just how close we are to these great apes. Read on for some surprising details about man’s (very, very) distant relative.

Get Reader’s Digest’s Read Up newsletter for more nature, travel, humor, tech and fun facts all week long.

Semi-wild rehabilitated Orangutan coming down from the trees to get food from tourists
Rita Enes/Shutterstock

They have a hairline

In many cases, it’s the physical traits, rather than the strictly genetic ones, that researchers say link orangutans so closely to humans. One of those traits? “Humans and orangutans actually have a hairline,” Jeffrey H. Schwartz, co-author of a paper on the connections between us, told National Geographic. That’s a stark contrast to virtually all other primates, which have a more gradual transition and less of a distinct stopping point where the face starts. That shared feature reflects signs of evolution we have in common with our ape cousins.

Bornean orangutan playing and hanging on the tree. Portrait shot. Bali, Indonesia.
Gekko Gallery/Shutterstock

They have similar mouth features

Orangutans share at least 28 physical traits with humans. That’s 26 more than chimps and 21 more than gorillas. A couple of these similar traits are inside our mouths: We’ve both got flat molars that are covered with a thick layer of enamel. Another interesting orangutan and human similarity? “A hole in the roof of the mouth that was supposedly unique to humans is also present in orangs,” according to Schwartz.

old orang utan monkey portrait while looking at you
Andrea Izzotti/Shutterstock

We suffer from similar signs of aging

Orangutans, as well as other great apes, often have overlapping signs of aging and disease pathology, according to a study published in Veterinary Pathology. Humans live longer than all other great apes, but other than that, we suffer from the same common signs of aging, including tooth, bone and muscle mass loss; sensory impairment; cardiovascular disease; hair loss and graying; frailty; and arthritis, a condition that can take on 100 different forms in humans.

Female orangutan sitting on the fence in Semenggoh Nature Reserve, Sarawak, Borneo, Malaysia
Mazur Travel/Shutterstock

They have greater brain asymmetry than previously thought

According to research cited by New Scientist, orangutans have greater asymmetry between the right and left hemispheres of their brains than previously thought. Science once assumed that humans were the only primate to have specialized brain hemispheres, but research by the Max Planck Institute for Evolutionary Anthropology in Germany found that great apes also share this evolutionary variation, though it’s less pronounced in chimpanzees.

Female orangutan and her baby in the rainforest
michel arnault/Shutterstock

They bond with Mom

Orangutans’ strong bond with their mothers is rivaled only by humans. According to the Orangutan Foundation International, primatologists think these animals have long “childhoods” because, like humans, they need to learn so much before they can live alone. Juvenile orangutans hang with mom till they’re about 8 years old and nurse for pretty much the whole time.

orangutan indonesia
Lintang Hakim/shutterstock

We share signs of pregnancy

Cheryl Knott, a biological anthropologist who studies orangutans in Gunung Palung National Park in Indonesia, made her own startling discovery about the similarities between humans and these shaggy red-haired great apes. Orangutans and humans “are so similar that Knott can use standard drugstore test kits on urine from female orangutans to determine whether they’re pregnant,” reported National Geographic.

An orangutan touching a human hand
marie martin/Shutterstock

We have a common ancestor

One of the most controversial things Schwartz and his fellow researcher, John Grehan, concluded in their study was that humans and orangutans share a common ancestor that is not shared with other great apes. “We infer that the human–orangutan common ancestor had established a widespread distribution by at least 13 Ma [mega annum, or million years],” Schwartz and Grehan wrote.

The orangutans are three extant species of great apes native to Indonesia and Malaysia. Orangutans are currently only found in the rainforests of Borneo and Sumatra. 
arul_nkh/Shutterstock

We laugh

“Perhaps the most humanlike behavior is the laughing by apes when they are being tickled,” Frans de Waal, a behavioral biologist and ethologist at Emory University, told Live Science. “It is low pitched compared to human laughter, but the facial expression and the waxing and waning of the laughing sounds are eerily human, to the point that those of us familiar with these vocalizations cannot stop ourselves from laughing too.”

Close up of orangutans, selective focus.
tristan tan/Shutterstock

They can recognize faces

Actually, this is not a trait that’s specific to orangutans, or to great apes; even sheep, cows and dogs can recognize one another’s—as well as humans’—faces. But since these other animals are all social, and orangutans are largely solitary creatures, the ability takes on special poignancy and scientific relevance, especially when considered in conjunction with the fact that orangutans can also recognize faces they last saw long ago, according to research published in PLOS One.

Funny portrait of a group of orangutans, including two mothers with their young offspring, enjoying a snack of sunflower seeds.
CherylRamalho/Shutterstock

They “talk” about the past

Recent findings suggest that orangutans can recall their history. As Science magazine reports, “When wild orangutans spot a predator, they let out a loud ‘kiss-squeak,’ a call that sounds like a human smooching.” It’s not just a sign of recognition. “That noise tells tigers and other enemies, ‘I’ve seen you,’ scientists believe, and it also lets other orangutans know danger is near.” Researchers also reported hearing orangutans making this call after the threat was over, which suggests that it’s not just humans who can “talk” about the past.

Orangutan and his son eating some dishes in the Spilok park
Unai Huizi/Shutterstock

They learn from each other

It wasn’t so long ago that humans believed we were the only species that taught each other things that related to our own specific experiences. Not so, according to Orangutan Foundation International. In fact, orangutan populations in Borneo “use handfuls of leaves as napkins to wipe their chins, while orangutans in parts of Sumatra use leaves as gloves, helping them handle spiny fruits and branches, or as seat cushions in spiny trees.”

A female orang-utan sharing a kiss with her baby in their native habitat. Rainforest of Borneo.
David Evison/Shutterstock

They pass that learning on to the next generation

Social learning that gets passed down through multiple generations is a building block of culture, and this trait has long been considered unique to humans. But according to research published in Current Biology, researchers concluded that geographical variations in orangutan behavior could be attributed to orangutans passing their social knowledge down through generations instead of primarily through genetic or environmental influences.

Why trust us

At Reader’s Digest, we’re committed to producing high-quality content by writers with expertise and experience in their field in consultation with relevant, qualified experts. We rely on reputable primary sources, including government and professional organizations and academic institutions as well as our writers’ personal experiences where appropriate. We verify all facts and data, back them with credible sourcing and revisit them over time to ensure they remain accurate and up to date. Read more about our team, our contributors and our editorial policies.

Sources: