Are Primates Really That Similar to Humans?
Most people are aware that primates are the closest living relatives to humans. Chimpanzees, gorillas, gibbons, orangutans and other monkeys all have unique characteristics, but together we are all part of the same order of mammals, Primatomorpha.
This distinct order of primates has evolved in different ways, but their behaviors and even their looks reveal some similarities to modern humans. When it comes down to the finer points — certain habits, emotions, reactions and physical developments — what’s the truth about how similar we are to primates?
How Were Humans and Primates First Linked?
As a species, we have come a long way in 25 million years. Evolutionary specialists, starting with Charles Darwin, have suggested humans evolved from other animals around 150 years ago. This theory was met with indignation by some people, but as more scientific evidence was studied, the similarities between humans and primates became too much to ignore.
Are Our Brains Alike?
Modern human brains evolved to be larger than primates, but our brains are structurally similar to that of a chimpanzee. And we're not just talking about skull shape. We're talking about cortical areas of reasoning, abstract thought and problem-solving.
What Other Physical Similarities Do We Have?
Sticking to the physical similarities for now, one of the most obvious similarities is that most primates can walk on two legs, just like humans. Their feet are more hand-like, which allows them to more easily jump and swing through their natural tree-based habitats. They also use their actual hands for many of the same things that humans do.
Which Primate Is Most Similar to Humans?
In terms of physical characteristics and behavior, the chimpanzee is the most similar primate to humans. Geneticists say that chimps share about 98.6% of their DNA with humans. This is significantly more than monkeys and other great apes.
Who Conducted the Earliest Studies?
Naturally, when humans became more interested — and more convinced — in the similarities between primates and humans, experiments began in a new field of study known as primatology. Many early studies didn’t follow acceptable practices to get answers, but science has come a long way, and many ethical studies in recent years have produced some fascinating results.
Did Primates Travel in Space?
Sadly, the similarities between primates and humans are so significant that primates were sent into space as test subjects to see if humans could survive the travel conditions. The first primate astronaut, a rhesus macaque called Albert, was sent up to an altitude of 39 miles in a rocket ship in 1948 and died from suffocation.
Do They Have Emotions Like Us?
Humans convey so much through their facial expressions, and those expressions are seen as uniquely human attributes to convey when we’re happy, sad, angry, excited and more. Primates don't have the same range or the same in depth meaning for facial expressions, but they do have other ways of showing their emotions.
Will Primates Do Tricks or Trade for Food?
What better way to bribe someone than with food? Humans are guilty of promising their children food treats as rewards for good behavior, and monkey trainers — and all kinds of other animal trainers — often enjoy great success using food as rewards during training.
What About Junk Food?
Unfortunately, primates seem to have developed the same affinity for junk food as humans. In parts of India and Africa where fast food joints have cropped up over the years, wild primates have been observed rooting through trash to find leftover chips and fried chicken to munch on.
Do They Know Right from Wrong?
The ability to distinguish between right and wrong is considered to be a concept that is unique to humans and learned in the formative childhood years. However, studies like one conducted by the University of Zurich show chimpanzees are well aware of what behaviors are appropriate.
Do Primates Recognize Faces?
Remarkably, primates have been observed to recognize their own faces when they are handed a mirror and look at it, which is something very few other animals can do. This shows that primates do have a sense of self like humans do.
Can Primates Understand Humans?
So, we have established that primates, particularly chimpanzees, do indeed experience the world similar to the way humans do. Using similar senses as our own, including touch, hearing, smell and sight, they enjoy food, fun, social interaction with friends and many other things considered "human."
Can They Learn Sign Language?
Among their own social groups, primates use vocalizations and body language to communicate with each other. This includes hugging, grooming, patting, hand-holding and fist-shaking. Even more impressive, they can use body language and sign language to communicate with humans. Koko the gorilla is probably the best-known example of a primate that was taught sign language.
What Makes Primates Laugh?
Primates have been observed to show a range of positive emotions, from relaxed facial expressions to bursting into laughter and rolling around on the floor! As laughter signals a sense of humor and understanding that something is funny, it’s remarkable that this trait is shared between primates and humans.
How Do Primates Learn?
Just like us humans, the formative years of a primate's life are all about learning. In particular, the first five years of a chimp’s life are the most important time for learning, and they do it through play, copying relatives — especially their mother — and socializing with other chimps.
Do They Have Playmates?
Human children spend hours running around playing and having fun — and so do the adorable babies of primates. For most animals, playful behavior such as play fighting is a kind of practice for real-life, adult situations.
Do Primates Play with Toys?
Primates have been observed to play with sticks, stones and other things in nature. When given human toys, they relish the opportunity to play with them. In a remarkable study conducted by Kim Wallen, a psychologist at Yerkes National Primate Research Center in Atlanta, Georgia, rhesus monkeys actually chose gender-specific toys.
Do Primates Get Angry Like Humans?
It has been regularly observed that primates can become angry and irritated, which is a typical fear or dominance response. Furthermore, primates, particularly chimpanzees, are the only species besides humans that have been observed in studies spanning 50 years to make coordinated attacks on other members of their own species.
Do Primates Express Control and Calm?
Biologists in the U.S. studied primates by using a game of "Ultimatum" and discovered that they share the same aversion to injustice as humans do. In the game, where equality prevails over benefits, the chimps would make fair offers and only accept fine and egalitarian offers from their peers.
Do They Get Protective Like Humans?
Monkeys do indeed get highly protective. This often applies to basic things such as food and environment, including not allowing other animals or rival primates to invade their territory and steal their food. Most significantly though, it applies to their protectiveness of their young. Adult primates have been known to kill young primates, either as revenge, an act of cruelty or elimination of a perceived threat.
Do Primates Like to Cuddle?
Primates that are classed by primatologists as being more "socially competent," such as bonobos, use cuddles and affection to calm others in distress. Along with other sympathetic reactions studied in bonobos, this leads to them being nicknamed the "empathetic apes."
Do Primates Pair for Life?
When it comes to choosing a friend or partner, studies from the University of Vienna found that primates can be quite selective. Like humans, they often choose a partner who shares similar personality traits, such as shyness or bravery, and are naturally drawn to the most social primates in order to better fit into the community.
What About Sex?
With primate behavior being so similar to human behavior in terms of socialization, power struggles and a whole load of emotions, it’s not surprising there are similarities in our sex lives. Primates have been observed engaging in deception to get what they want, including the attention of a female, and sometimes even apologize to the injured party if they cause upset.
Do They Mourn Like Humans?
Heartbreakingly, primates display significant signs of mourning when they lose one of their friends or family members. Due to their strong social bonds and their need for a strong community, there's an element of social preservation in play, but deeper than that, primates become visibly upset on a personal level when they lose someone close.
Their Memories Can Fade Like Humans
One element of being human is that no matter what we do to fight it, we know as we get older that we will experience inevitable deterioration with age. Of course, primates show physical signs of aging — aching joints, failing eyesight, etc. — but this also occurs with cognitive function.
Do They Have a Hierarchy?
As well as being aware of particular ways to act to gain and keep friends and maintain harmony in a group, primates use social skills to their advantage to gain prestige. If primates know what others in their community want and they act on that, they know they can gain more status.
Primates Get Excited by New Things
Just like human babies, primate babies are fascinated by the new world around them, and they want to touch, feel, taste and play with all sorts of things to figure them out — even if it means getting bitten by some red ants or knocked down by another monkey.
They Use Important Learnings
An experiment in the 1960s showed that primates learn cause-and-effect concepts. In the trial, a group of rhesus monkeys learned that if they pulled a chain, they would get a serving of food. However, once a new monkey was introduced to the group, he started getting an electrical shock whenever the lever was pulled.
Are There More Studies on the Similarities?
Researchers are keen to learn more about the finer points of primates' emotional and social behaviors to see just how similar they are to humans. A study published in Science Daily last year looked at how monkeys communicate threats.
Can Humans and Primates Be Friends?
Human children tend to have the best success in befriending primates, indicating they can see the vulnerability and innocence of younger humans. National Geographic, for example, reported on a young boy in India, who was accepted into a group of gray langur monkeys.