Melissa Hogenboom wrote for the BBC: “We once viewed ourselves as the only creatures with emotions, morality, and culture. But the more we investigate the animal kingdom, the more we discover that is simply not true. Many scientists are now convinced that all these traits, once considered the hallmarks of humanity, are also found in animals. If they are right, our species is not as unique as we like to think. [Source: Melissa Hogenboom, BBC, July 3, 2015 |::|]

“Of course not everyone agrees. A species, by definition, is unique. In that trivial sense humans are unique, just as house mice are unique. But when we say humans are unique, we mean something more than that. Throughout history humans have created a seemingly impenetrable barrier between us and other animals. As the philosopher Rene Descartes wrote in the late 1600s: "animals are mere machines but man stands alone". |::|

“Charles Darwin was one of the first to speak out against this idea. In The Descent of Man, he wrote: "There is no fundamental difference between man and the higher mammals in their mental faculties" and that all the differences are "of degree, not of kind". He later extensively documented the similarities between human facial expressions and those of animals. "If a young chimpanzee be tickled," he noted, "as is the case of our young children a more decided chuckling or laughing sound is uttered". He also observed that chimpanzees' eyes wrinkle, sparkle and grow brighter when they laugh.” |::|

“His thoughts were later forgotten or ignored. By the 1950s animals had been reduced to unemotional machines with mere instincts. The behaviourist BF Skinner thought all animals were much the same. "Pigeon, rat monkey, which is which, it doesn't matter." He said that the same rules of learning would apply to them all. At the time, there was a prevailing attitude that they lacked intelligence. There was a taboo against attributing emotions to animals, says Frans de Waal of Emory University in Atlanta, US.

Websites and Resources on Hominins and Human Origins: Smithsonian Human Origins Program ; Institute of Human Origins ; Becoming Human University of Arizona site ; Talk Origins Index ; Last updated 2006. Hall of Human Origins American Museum of Natural History ; Wikipedia article on Human Evolution Wikipedia ; Human Evolution Images; Hominin Species ; Paleoanthropology Links ; Britannica Human Evolution ; Human Evolution ; National Geographic Map of Human Migrations ; Humin Origins Washington State University ; University of California Museum of Anthropology; BBC The evolution of man"; "Bones, Stones and Genes: The Origin of Modern Humans" (Video lecture series). Howard Hughes Medical Institute.; Human Evolution Timeline ; Walking with Cavemen (BBC) ; PBS Evolution: Humans; PBS: Human Evolution Library; Human Evolution: you try it, from PBS; John Hawks' Anthropology Weblog ; New Scientist: Human Evolution; Fossil Sites and Organizations: The Paleoanthropology Society; Institute of Human Origins (Don Johanson's organization); The Leakey Foundation; The Stone Age Institute; The Bradshaw Foundation ; Turkana Basin Institute; Koobi Fora Research Project; Maropeng Cradle of Humankind, South Africa ; Blombus Cave Project; Journals: Journal of Human Evolution; American Journal of Physical Anthropology; Evolutionary Anthropology; Comptes Rendus Palevol ; PaleoAnthropology

Chimpanzee Social Behavior

Chimpanzees have a highly fluid social organizations. Sometimes they wander around by themselves. Sometimes they forage in groups with 30 or more chimps. Sometimes they bang on the buttresses of large trees to announce their presence throughout the forest.

Chimpanzees shake hands, back slap, yawn, hug, dance and embrace one another. They also pat each other on the back, hold hands and even kiss each other as a greeting. When old friends haven't seen each other for a long time they run toward each, look each other in the eye, rocking back and forth on their feet while their hair stands on end. Finally, they fling their arms around each other with a welcoming embrace.

Chimps will sometimes sit on logs as if they were chairs. and even keep them as possessions. If another chimp is angry sometimes they will heave the “chair” into the forest. In 1964, Goodall recorded an example of "planning" and "intelligence" when a chimpanzee named Figan "kidnaped" another chimpanzee to get the rest of the group to follow him to another location.

When threatened chimpanzees bare their teeth, hurl sticks and urinate on their attackers. When they are nervous they often reach out and touch one another. Bowing is a chimpanzee gesture of submission. Sympathy towards a friend bloodied in a fight can be expressed with a grooming session. Chimps who are good friends often pass food to each other with their feet and greet each other with soft pants and an extended wrist like a debutante presenting her hand to be kissed.

Figan, a chimpanzee observed by Goodall, cemented his position as dominate male with the help of his brother Faben. When Faben disappeared, Figan had more difficulty fending off challengers but still managed to hold onto power. Japanese chimpanzee researcher Toshida Nishida observed one male chimpanzee that swung the balance of who was the dominate male in the group by allying himself first with an elderly chimpanzee and later with a challenger. "His reward," Nishida said, "was access to estrous females with the interference of his less astute superiors."

The Gombe research team observed similar behavior by a chimp named Goblin that kept changing his alliance with two males—Freud and Frodo—that challenged each other for the position of alpha male. "Goblin sides with whoever looks most powerful," Goodall told National Geographic. "So no matter who wins, he can’t lose. Meanwhile he has access to any female he wants, right in front of everyone. Neither Freud nor Frodo will stop him, or they might lose his support. So smart."

Orangutan Customs and Culture

Orangutans pass on behavior from one generation to the next. Some of these “customs” are unique to particular groups which some scientist argue is an expression of “culture," which is defined as the ability to invent new behaviors adopted by a group which are then passed down to succeeding generations. It was previously thought that only humans and chimpanzees possessed “culture."

There are a number of examples of orangutans living in one area that possess culture and customs that other groups don't have. One group at Gunung Palung National Park in Borneo, for example, threatens strangers by making kiss-squeaking noise into a handful of leaves. In Sumatra, orangutans use sticks to pry nutritious seeds from prickly, difficult-to-eat Neesia fruits. Others make a raspberry-like noise before turning in for the night, use their fists to amplify sound, employ leaves as gloves when handling spiny fruits, dip leaves in a hole with water and lick the leaves, use leaves as napkins and employ sticks to poke out sections of termite nests.

What is remarkable about the finding compared to other apes is that orangutans are much less social than chimpanzees and humans. Galdikas wrote in Science, “If orangutans have culture, then its tells us that the capacity to develop culture is very ancient...orangutans separated from our ancestors and from the African apes many millions of years ago." The study suggests “they may have had culture before they separated."

Ape Experiments

Elizabeth Kolbert wrote in The New Yorker: “The Leipzig Zoo lies on the opposite side of the city from the Institute for Evolutionary Anthropology, but the institute has its own lab building on the grounds, as well as specially designed testing rooms inside the ape house, which is known as Pongoland. Since none of our very closest relatives survive (except as little bits in us), researchers have to rely on our next closest kin, chimpanzees and bonobos, and our somewhat more distant cousins—gorillas and orangutans—to perform live experiments. (The same or, at least, analogous experiments are usually also performed on small children, to see how they compare.) One morning, I went to the zoo, hoping to watch an experiment in progress. That day, a BBC crew was also visiting Pongoland, to film a program on animal intelligence, and when I arrived at the ape house I found it strewn with camera cases marked “Animal Einsteins.” [Source: Elizabeth Kolbert, The New Yorker, August 15, 2011]

“For the benefit of the cameras, a researcher named Héctor Marín Manrique was preparing to reënact a series of experiments he’d performed earlier in a more purely scientific spirit. A female orangutan named Dokana was led into one of the testing rooms. Like most orangutans, she had copper-colored fur and a world-weary expression. In the first experiment, which involved red juice and skinny tubes of plastic, Dokana showed that she could distinguish a functional drinking straw from a non-functional one. In the second, which involved more red juice and more plastic, she showed that she understood the idea of a straw by extracting a rod from a length of piping and using the pipe to drink through. Finally, in a Mensa-level show of pongid ingenuity, Dokana managed to get at a peanut that Manrique had placed at the bottom of a long plastic cylinder. (The cylinder was fixed to the wall, so it couldn’t be knocked over.) She fist-walked over to her drinking water, took some water in her mouth, fist-walked back, and spit into the cylinder. She repeated the process until the peanut floated within reach. Later, I saw this experiment re-staged with some five-year-old children, using little plastic containers of candy in place of peanuts. Even though a full watering can had been left conspicuously nearby, only one of the kids—a girl—managed to work her way to the floating option, and this was after a great deal of prompting. (“How would water help me?” one of the boys asked, just before giving up.)”

Human Children Versus Apes

orangutan experiment in 1907

Elizabeth Kolbert wrote in The New Yorker: “One way to try to answer the question “What makes us human?” is to ask “What makes us different from apes?,” or, to be more precise, from nonhuman apes, since, of course, humans are apes. As just about every human by now knows—and as the experiments with Dokana once again confirm—nonhuman apes are extremely clever. They’re capable of making inferences, of solving complex puzzles, and of understanding what others are (and are not) likely to know. When researchers from Leipzig performed a battery of tests on chimpanzees, orangutans, and two-and-a-half-year-old children, they found that the chimps, the orangutans, and the kids performed comparably on a wide range of tasks that involved understanding of the physical world. For example, if an experimenter placed a reward inside one of three cups, and then moved the cups around, the apes found the goody just as often as the kids—indeed, in the case of chimps, more often. The apes seemed to grasp quantity as well as the kids did—they consistently chose the dish containing more treats, even when the choice involved using what might loosely be called math—and also seemed to have just as good a grasp of causality. (The apes, for instance, understood that a cup that rattled when shaken was more likely to contain food than one that did not.) And they were equally skillful at manipulating simple tools. [Source: Elizabeth Kolbert, The New Yorker, August 15, 2011]

“Where the kids routinely outscored the apes was in tasks that involved reading social cues. When the children were given a hint about where to find a reward—someone pointing to or looking at the right container—they took it. The apes either didn’t understand that they were being offered help or couldn’t follow the cue. Similarly, when the children were shown how to obtain a reward, by, say, ripping open a box, they had no trouble grasping the point and imitating the behavior. The apes, once again, were flummoxed. Admittedly, the kids had a big advantage in the social realm, since the experimenters belonged to their own species. But, in general, apes seem to lack the impulse toward collective problem-solving that’s so central to human society.”

“Chimps do a lot of incredibly smart things,” Michael Tomasello, who heads up the institute’s department of developmental and comparative psychology, told the The New Yorker. “But the main difference we’ve seen is ‘putting our heads together.’ If you were at the zoo today, you would never have seen two chimps carry something heavy together. They don’t have this kind of collaborative project.”

Orangutan Dreams, Aggression and Self Awareness

Orangutans and chimpanzees are the only two animals that pass the mark test, a measurement of being self aware. In this test an animal is anaesthetized and marked with an odorless dye above an eyebrow or ear. The animal passes if it touches the mark after being shown a mirror after it wakes up. Apes can recognize themselves in a mirror while monkeys think they are confronted with another monkey.

Apes may dream; they have rapid eye movement. One naturalist described a young orangutan who woke up screaming as if they had just had a nightmare. The orangutan’s turns out had witnessed his mother being shot down from a tree by tribesman and killed, skinned and eaten before his eyes. Orangutans are also quick learners but sometimes at the cost of unanticipated cost. An orangutan couple in Russia followed instructions from a video on good patenting and then became addicted to television and neglected each other.

Bill Brubaker wrote in Smithsonian magazine, Males are frighteningly unpredictable. Galdikas recalls one who picked up her front porch bench and hurled it like a missile. "It's not that they're malicious," Galdikas assures me, gesturing toward the old bench. "It's just that their testosterone surge will explode and they can be very dangerous, inadvertently." She adds, perhaps as a warning that I shouldn't get too chummy with Tom and Kusasi, "if that bench had hit somebody on the head, that person would have been maimed for life." [Source: Bill Brubaker, Smithsonian magazine, December 2010]

When I visited Gunung Leuser National Park in Sumatra my guide told me several stories about aggressive orangutans. The guide said once a large male started chasing him down a trail and rolled itself into a ball and somersaulted down a downhill section of trail to catch up to the guide, who said he was vigorously man-handled by the ape but emerged more or less uninjured.

Chimpanzee and Gorilla Murder

According to some estimates a third of all male chimps are killed in attacks by other chimps. Several cases of chimpanzee homicide have been documented. Chimps are very strong. They can kill with their hands and feet In 1995, Goodall told National Geographic, "When I first started at Gombe, I though the chimps were nicer than we are. But time has revealed that they are not. They can be just as awful."

Goodall said: If a patrol of chimpanzees “meets up with a group from another community, both sides, after exchanging threats, are likely to withdraw discreetly back into home ground. But if a single individual is encountered, or a mother an child, then the patrolling males usually chase and, if they can, attack the stranger. Ten very severe attacks on mothers or old females have been recorded since 1970; twice the infants of the victims were killed; one other infant died from wounds.” Researchers have observed one of group of chimpanzees holding a victim down while others attacked it, even ripping its flesh with their teeth.

Diane Fossey's assistant Peter Veit witnessed an attack by a male gorilla on a diseased female that resulted in death. After she was clearly dead the male repeatedly jumped on her and dragged her body around a trampled down clearing. The incident began when the male and a dominant female in the group began beating their chests near the sickly female, who appeared to have been near death anyway. The male killed her by pounding on her chest until she "let out her only—and also—last vocal sound, a death rattle, as if through stuffed nostrils." The silverback in the group didn't do anything until the female was already dead. The dead female’s 3½ year-old, who watched the entire event, tried to suckle her, also, after she was dead. When Veit left the site and returned 18 hours later he found the murderer still beating his chest by the dead body. Shortly thereafter the entire group wandered off.

Infanticide has been observed among gorillas. Usually it is done by a male to infants fathered by different males to free the nursing females for breeding. The death unusually is quick: a crushing bite to the skull or groin: Fossey said "I now believe infanticide is the means by which a male instinctively seeks to perpetuate his own lineage by killing another male's progeny in order to breed with the victim's mother." Fossey observed the silverback in one group kill an infant in another group that was dissolving so he could claim the mother. Infanticide, Fossey said, accounted for the death of 38 infants over a 13-year period.

Morality and Fairness Among Animals

Melissa Hogenboom wrote for the BBC: “Chimps' social skills are the basis for another behaviour once thought to be uniquely human: morality. Morality can be said to encompass fairness, altruism and empathy. For centuries our moral codes have been crucial to our notion of humanity. We have long believed that our heightened moral reasoning and empathy sets us apart from the beasts.[Source: Melissa Hogenboom, BBC, July 3, 2015 |::|] “We know that children have a strong sense of fairness from an early age. For instance, they will share with friends, even if there is an obvious cost to them. They also seem to be innately altruistic: they will help pick up dropped objects without any prompts from as young as 14 months. But other animals have an innate sense of fairness, too. Capuchin monkeys know what's fair and what's not. |::|

“In 2003 de Waal published research looking into how capuchin monkeys reacted to an unfair payment. After two monkeys had completed the same task, both would happily accept a cucumber as a reward. But when one was randomly given a more delicious grape instead, the other was not happy and began to refuse the cucumber. Chimpanzees behave in a similar way. But what if a chimpanzee controlled the reward instead of a human experimenter? We know that for the most part, they act selfishly when it comes to food. They are known to steal or hide it from rivals.

De Waal’s Capuchin Monkey Fairness Experiment

Capuchin monkey eating a banana

Capuchin monkeys have a strong sense of fairness, even going strike over pay issues. In a famous experiment they refused to do a task and threw down tools their when they saw another monkey get a bigger reward for doing the same task. John Whitfield wrote in Nature: “The experiments show that notions of justice extend beyond humans, says Sarah Brosnan of Emory University in Atlanta, Georgia. This is probably an innate ability that evolved in our primate ancestor, she believes: "You need a sense of fairness to live in large, complex groups." Brosnan and her colleague Frans de Waal taught brown capuchin monkeys (Cebus apella) to swap plastic tokens for food. Normally, monkeys were happy to exchange a token for some cucumber. [Source: John Whitfield, Nature, September 18, 2003 ]

“But the monkeys took offence if they saw a neighbour getting a grape for a token. In about half of such trials, the short-changed capuchin either refused to hand over its token, or rejected the reward. Some threw the token or cucumber clean out of their cage. The animals' umbrage was even greater if another monkey got a grape for nothing. About 80 percent rebelled in some way in this situation. "It's a really neat discovery," says primatologist Charles Janson of the State University of New York at Stony Brook. "The monkey is clearly paying attention to what its neighbour is doing, and realizing that it's getting a better reward."

“But it's not clear how important this ability is in the forests of South America, where the brown capuchin lives, warns Janson. "Capuchin monkeys can learn to do all sorts of things in captivity that they never do in the wild," he says. Capuchins don't hold a grudge, says Brosnan. They worked with her on future trials, and the inequality did not create trouble between animals. "The monkeys were clearly not thrilled, but they weren't visibly anxious," she says.

“Only female monkeys show this pique, the researchers found. Males were much less sensitive to inequality. Their minds may have been on other things, says Janson: "Males care about sex, and females care about food. The males might not consider the food differences worth worrying about." Previous experiments with humans have shown that they become less cooperative if treated unfairly, and punish uncooperative people even if their own reward declines as a result. This is akin to a monkey throwing away the cucumber that it has already worked for. Brosnan is now studying chimps to see if they share this trait with us and capuchins. “

Cooperation and Helpfulness Among Chimps and Animals

Melissa Hogenboom wrote for the BBC: “Chimpanzees also seem to be instinctively helpful. Just like young infants, chimpanzees will help humans reach for out-of-reach objects. A 2013 study found that they also know the value of cooperation. They will share food even if there is nothing obviously in it for them. The study found that they will split a reward equally, just as humans do. In one task chimpanzees shared bananas in the same way that humans share money. They also help each other. Chimpanzees will unlock a door that leads to food for a mate, even if the one doing the unlocking would not get any. In the wild researchers have witnessed chimpanzees helping disabled group members, adopting unrelated orphans and helping friends escape from poachers' snares. [Source: Melissa Hogenboom, BBC, July 3, 2015 |::|]

“This sense of altruism must run deep in the animal kingdom, because rats will also save a friend from being soaked with water, even if it means getting wet themselves. These studies suggest that cooperation is a useful survival trait for many species. If humans, chimps and rats all cooperate, the common ancestor of all three may have done so too. |::|

“"Chimpanzees live in a rich social environment, they depend on each other," says Felix Warneken of Harvard University in the US. "It does not require a big society with social norms to elicit a deep-rooted sense that we care about others." The long-held view that chimps are selfish and mean is no longer acceptable, says de Waal. "People say that morality comes from God, from religion," he says, but we can clearly see the roots of morality in many other species.

Chimpanzees Are Helpful, But Only When Asked

In a paper published in PNAS in February 2012, primatologist Shinya Yamamotoa and colleagues demonstrated that chimpanzees are only helpful to a point: they are usually not very helpful if it means giving up valued things like food, even if they've got more than they need. This true is even between a mother and her infant! Jason G. Goldman wrote in Scientific American: “Why do chimpanzees seem so reluctant to help others? One possible explanation is that they're unable to understand the goals of another individual, resulting in an inability to create any sort of shared intentionality between two individuals. To that end, the researchers write, "many still believe that humans are unique in this respect because we are the only animal species endowed with unique 'theory of mind' abilities enabling us to understand the goals and to share the intentions of others." [Source: Jason G. Goldman, Scientific American, February 13, 2012, Yamamoto S, Humle T, & Tanaka M (2012). “Chimpanzees' flexible targeted helping based on an understanding of conspecifics' goals.” Proceedings of the National Academy of Sciences (PNAS) \~]

“Yamamotoa and the other researchers set up an experiment designed explicitly to address this possibility. The first chimpanzee was given a task to accomplish in order to receive a juice reward. The task required the use of one of two types of tools: a stick or a straw. The stick and the straw, however, as well as five other items were found not in the first chimpanzee's booth, but in the second chimp's booth. There was a small opening between the two booths where the second chimp could pass the necessary tool to the first. By itself, this could test whether or not the second chimp was willing to help the first chimp.\~\

“But to see whether the ability to understand the goal of another individual modulates the potential to help, the researchers created two further conditions: half the time, the barrier separating the two booths was a transparent window, and half the time it was a completely opaque wall. If chimpanzees modulate their responses to a help request based on whether or not they can see the goal of another individual, then they should give the appropriate tool more often when in the transparent window condition. \~\

“During the transparent window condition, the chimpanzees were more likely to offer up the appropriate tool (e.g. a stick during the stick condition, or a straw during the straw condition) than any of the other tools. This result itself shows that the chimpanzees were able to understand which tool their partner would need in order to solve a given task. Importantly, ninety percent of tool offers occurred only after a request was given by the first chimpanzee, suggesting that while chimpanzees may not spontaneously engage in helping behaviors, direct requests are effective in soliciting assistance. \~\

“The results from the opaque window condition might provide some insight into how the chimps determine which tools to provide when asked for help. As in the first condition, chimps were extremely likely to offer a tool after a request was made. In fact, one of the objects (even if not the useful one) was given following a request 98.5 percent percent of the time, on average. While they were more likely to offer one of the two useful tools - the stick or the brush - compared with the other items, the tool that the first chimpanzee needed was not predictive of the tool they were given. In other words, the chimps were not able to infer the precise goals of their partner. They were only able to understand that their partner needed a tool, in a generic sort of way. The one exception to this trend was a chimpanzee named Ayumu, who actually pulled himself up to see through the small window, effectively turning this "cannot see" condition into a "can see" condition. \~\

“The chimps' willingness to help was similar in both conditions. That is, following a request for help, the chimpanzees were equally likely to offer a tool whether or not they could see their partner's situation. While a request might be sufficient to motivate a chimpanzee to help, requests did not provide enough information for the chimps to help effectively. The researchers point out that Ayumu's behavior - selecting the appropriate tool only after looking through the hole in the wall - further reinforces the notion that chimps require visual information in order to help. The researchers conclude, "even without shared intentionality and sophisticated communicative skills, such as language or pointing, chimpanzees can understand others’ goals when situations are visibly obvious and understandable."

“In a sense, though, the findings from this experiment are a bit contradictory: even when they could not visually assess their partner's situation, the chimpanzees were willing to help, and even persisted in offering multiple tools. But when given visual access to their partner's booth, they rarely helped unless directly requested. That is, the ability to infer a partner's goals is not the limiting factor in chimpanzees' altruistic behavior. So...what is?”

Humans More Helpful Than Chimpanzees?

Melissa Hogenboom wrote for the BBC: “Comparative studies between humans and chimps show that while both will cooperate, humans will always help more. Children seem to be innate helpers. They act selflessly before social norms set in. Studies have shown that they will spontaneously open doors for adults and pick up "accidentally" dropped items. They will even stop playing to help. Their sense of fairness begins young. Even if an experiment is unfairly rigged so that one child receives more rewards, they will ensure a reward is fairly split. [Source: Melissa Hogenboom, BBC, July 6, 2015 |::|]

“We know that chimpanzees also work together and share food in apparently unselfish ways. However, Michael Tomasello of the Max Planck institute for Evolutionary Anthropology in Leipzig, Germany, says they will only cooperate if there is something in it for them. "Humans do that too, but in addition they care about what their partner gets. In some experiments we have children as young as 14-18 months who seem to expect their partner to collaborate in certain ways and who share in ways chimps don't." |::|

“Human children are less selective about who they share with. Chimpanzees though, largely only share with close relatives, reciprocating partners or potential mates. Felix Warneken of Harvard University in Cambridge, US, differentiates it like this. Children are "proactive", that is, they help even when presented with only very subtle cues. Chimpanzees though, need more encouragement. They are "reactive": they will hand over objects but only after some nudging. |::|

“Something must have happened in our evolution, Tomasello says, to make humans increasingly reliant on each other. Our brains needed fuel to get bigger and so collaborative hunting may have played a key role in that. Our advanced teamwork may simply reflect our long history of working together to get food.” |::|

Evil and Goodness Among Chimpanzees

chimpanzee teaching tool use in Senegal

Melissa Hogenboom wrote for the BBC: “Of course, with the good comes the bad. It would be misleading to only consider chimpanzees as helpful, moral creatures. Just like us, they have a dark side. There are many instances of fighting, murder and even infanticide. Their society is built upon a complex, hierarchical social world where it is important to keep friends close. That means chimps can get manipulative. [Source: Melissa Hogenboom, BBC, July 3, 2015 |::|]

“ De Waal has called them "Machiavellian", in reference to the deceitful power-grabbing techniques described by historian and philosopher Niccolo Machiavelli. He saw that a dominant male chimpanzee, who had become powerful with the help of friends, became jealous if these allies associated with his rivals. In response, the male would keep them apart. "As soon as his best buddy starts grooming his rival he gets very upset and breaks it up," says de Waal. "That's a 'divide and rule' strategy." |::|

“These insights all suggest that chimpanzees are socially aware and understand each other's behaviour. But how good are they? Humans can recognise the mental states of others, an ability psychologists call "theory of mind". We can figure out what others are thinking and what their intentions are, and infer what another person does or does not know. |::|

“Children learn to do this from a young age, and there is now a lot of evidence that great apes possess many of these mind-reading skills. For example, a subordinate chimpanzee will only pick up a tasty banana if he can do so without being seen by a more dominant chimp. The subordinate knows that the dominant chimp would claim it. |::|

“We are not the only ones who can think about others as individuals with goals Chimps also have some understanding of human minds. They can tell the difference between a person who is unwilling to give them food and a person who is unable to so. |::|

“The latest line of evidence in this field shows that, after food is taken away from them, chimps will steal it back from an opaque box which the experimenter cannot see into. They leave the food in the clear box alone. Clearly, we are not the only ones who can think about others as individuals with goals, intentions and perceptions, says Katja Karg of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, the lead author of the study. |::|

“The next step is to look at whether orang-utans have the same ability, says Karg. We split from them about 14 million years ago, so if they do, it would suggest our mind-reading skills are ancient. Knowing someone else's mental state also requires a conscious awareness of your own. That suggests that chimpanzees also have a degree of conscious awareness. They are not the only ones. So far the ability has been found in many other apes, dolphins, Asian elephants and the European magpie.” |::|

Orangutan Intelligence and Mental Life

Orangutans in laboratory situations have learned sign language about as fast and effectively as their gorilla and chimpanzee counterparts. They were able to identify objects, answer questions and explain what they wanted to eat. When orangutans in the wild encounter humans for the first time they tend to drop branches on them, smack their lips loudly and make other vocalizations.

Orangutans show cognitive complexity and flexibility rivaling that of chimps and maintains cultural traditions in the wild. "Azy has a rich mental life," Rob Shumaker told National Geographic of his study subject and friend of 25 years. "Orangutans are on equal cognitive footing with African apes, or even surpass them on some tasks."

Jennifer Holland wrote in National Geographic: “Not only does Azy communicate his thoughts with abstract keyboard symbols, he also demonstrates a "theory of mind" (understanding another individual's perspective) and makes logical, thoughtful choices that show a mental flexibility some chimpanzees lack. In the wild, orangutans keep innovative cultural traditions: Some groups construct foraging tools for extracting insects from tree holes; others use leaves as rain hats or napkins, wad them up as pillows, or line their hands with them when climbing a spiky tree. And in rare instances orangutans will twist leaves into bundles and cradle them like dolls. [Source: National Geographic , March 2008]

Orangutans and Human-Learned Behavior

Orangutans have picked up quite a few habits from their human interlopers. They have learned to open locks, row boats and even cook pancakes One particularly well-mannered animal even learned to open packages by making nice neat tears in the corners (most orangutans apes aren't so adept; they open packages by ripping them to shreds). Some have even improved on human technology. One female used a digging stick to pull pieces of burning charcoal from a fire. When the burning wood cooled she munched away on it as if it were popcorn.

One ate rice with a fork and spoon, blew out candles, played with kittens and kissed them on the lips. Another mixed pancakes with more sugar than most recipes call for. Others still washed clothes, rung them out and waited until they were dry before putting them on. They only worrisome habit of the latter was that she dunked her socks in coffee before she put them on.

Orangutans Troublemakers

Orangutan make lousy house mates. Galdikas and Brindamour complained that the orangutans that stayed with them ate, drank and ripped open anything the can get their hands on; opened childproof drug containers; and squeezed out all the contents of glue bottles and toothpaste tubes. Not only did the orangutans sleep on their bed they also tore open the mattresses and pillows to get at the edible seeds on the inside. Closing the windows and doors wasn't enough to keep them out. The orange apes simply tore down the walls and knocked holes in the roof to get in.

The problems didn't stop there. They ate candles, drank shampoo and sucked on batteries like lifesavers. Usually not satisfied with drinking milk they also like to gargle with it and spit it out all over each other. One had a fancy for flashlight bulbs and another like to suck all the ink out of fountain pens.

Orangutans also like to play with dogs, cats and small children. They enjoy kissing and scratching their playmates but what seems to give the orangutans the greatest pleasure is placing their friends on their head. In zoos, stressed out orangutans respond well to aroma therapy and are particularly relaxed by rose oil.

Orangutans have been killed for raiding crops. Other have their fingers chopped for stealing eggs. Humans who have been attacked or injured by orangutans usually provoked the animals in some way.

Study Finds Orangutans Plan Trips and Map Out Routes

Seth Borenstein of Associated Press wrote: “It's the ape equivalent of Google Maps and Facebook. The night before a big trip, Arno the orangutan plots his journey and lets others know where he is going with a long, whooping call. What he and his orangutan buddies do in the forests of Sumatra tells scientists that advance trip planning and social networking aren't just human traits. [Source: Seth Borenstein, Associated Press, September 11, 2013]

“A new study of 15 wild male orangutans finds that they routinely plot out their next day treks and share their plans in long calls, so females can come by or track them, and competitive males can steer clear. The researchers closely followed the males as they traveled on 320 days during the 1990s. The results were published Wednesday in the journal PLoS One.

“Typically, an orangutan would turn and face in the direction of his route and let out a whoop, sometimes for as long as four minutes. Then he'd go to sleep and 12 hours later set on the heralded path, said study author Carel van Schaik, director of the Anthropological Institute at the University of Zurich. "This guy basically thinks ahead," van Schaik said. "They're continuously updating their Google Maps so to speak. Based on that, they're planning what to do next."

“The apes didn't just call once, but they keep at it, calling more than 1,100 times over the 320 days. "This shows they are very much like us in this respect," van Schaik said. "Our earliest hominin ancestor must have done the same thing." Scientists had seen such planning in zoos and controlled experiments, but this study provides solid evidence of travel planning in the wild, said Frans de Waal of Atlanta's Emory University, who was not part of the study.

“Van Schaik said he and colleagues happened upon the trip calls by accident nearly 20 years ago, first with the dominant male Arno, who they followed more than the other 14 males. They waited to publish the results because he thought few people would believe orangutans could do such planning. But in recent years, the lab and captivity studies have all shown such planning. Based on previous studies and monitoring, van Schaik figured the male lets the world know his plans so females can come to him or stay close. Some females may want to stay within earshot in case they are harassed by other males and need protection. Others can come to mate."

Orangutan Short-Circuits Electric Fence in Zoo 'Escape'

In May 2009, The Telegraph reported: “An "ingenious" 137-pound (62-kilogram) orang-utan used a branch to short-circuit an electric fence and escape from an Australian zoo only to change her mind and return to her enclosure. The ape, a 27-year-old female named Karta, jammed a stick into wires connected to the fence and then piled up debris to climb a concrete and glass wall at the Adelaide Zoo. [Source: The Telegraph, May 10, 2009]

Peter Whitehead, the zoo's curator, said: "You're talking about an animal that's highly intelligent. "We've had issues with her before in normal day-to-day operations where she tries to outsmart the keepers. She's an ingenious animal." Mr Whitehead told reporters that Karta sat on top of the fence for about 30 minutes before apparently changing her mind about the escape and climbing back into the enclosure.

"I think when she actually got out and realised where she was ... she's realised she shouldn't be there so then she's actually hung onto the wall and dropped back into the exhibit," he said.

Karta came within a few yards (meters) of visitors, who were the first to notice the animal's escape bid. Whitehead said the animal was not aggressive, but the zoo was cleared as a precaution, and veterinarians stood by with tranquilliser guns in case of trouble. Officials at the zoo in the southern city of Adelaide would conduct a "thorough review" of the escape bid and it was likely some vegetation that could be used in a future try for freedom would be removed from Karta's enclosure.

illustration from 1900

Like Humans, Apes Seem to Accept False Beliefs of Others

In a study published in 2016, great apes showed that have key abilities to see the world from point of view of others— a trait that once was considered uniquely human. Seth Borenstein. Of Associated Press wrote: “An international study found that chimpanzees, bonobos and orangutans seem to have this ability, even when they know that point of view is dead wrong. It’s called theory of mind, or the ability to know that others have different beliefs and perspectives. [Source: Seth Borenstein. Associated Press, October 7, 2016 /*]

“Researchers in the Japan, the United States, Germany and the United Kingdom put a specific part of theory of mind to the test — understanding that someone else may have false beliefs — and the apes passed, according to a study in Science. While apes had shown other aspects of understanding others’ perspectives, previous studies had not shown them to grasp the complex concept of understanding others’ false beliefs, said study authors Christopher Krupenye and Fumihiro Kano. It’s a concept humans develop around age 4 or 5. /*\

“Researchers tracked the eye movements of the apes as they watched 40-second movies that showed someone in a King Kong costume trying to fool a man. The man watches King Kong either hide a rock in a box or — in a different version of the experiment — hide himself in a hay bale. Then, after the man leaves, King Kong moves the rock or moves out of the bale. So at this point, the man doesn’t know the rock or King Kong has moved — but the ape watching the movie does. When the man returns, the ape looks at where the man last saw the rock or King Kong, showing that it can anticipate the man’s false belief that the rock or King Kong remains in the same place. /*\

“That shows that the ape is getting the concept of others’ false beliefs, and this is a “critical” aspect of cognition, said Kano, a comparative psychologist at the University of Kyoto. Apes have some understanding of others’ actions and can predict others’ actions even when those individual are acting on misinformation,” said Krupenye, who conducted psychological research at Duke University and is now at the Max Planck Institute in Germany. “This kind of skill is central to a lot of sophisticated human behavior that we use in cooperative context and culture and communications.” But this may not be a full understanding of others’ false beliefs, Kano cautioned. /*\

“Yale cognitive science professor Laurie Santos called the test results “really remarkable” and “very surprising” because tests in the past have not found primates understanding someone else’s false beliefs. But Santos said she’s reserving judgment because the study’s sample size is small — 29 apes — and there is no good explanation why the apes pass this test and failed other, similar ones. Joel Fagot and Raphaelle Malassis at Aix-Marseille University said in an email that it was “a very exciting study on an important question, but this study is probably not THE definitive demonstration of false belief in apes.”“ /*\

Chimps and Orangutans Experience Midlife Crises?

A study published in 2012 in the journal Proceedings of the National Academy of Sciences suggests the captive apes experience a kind of “mid-life crisis” and their well-being declines in middle age but picks up as they approach old age Ian Sample wrote in The Guardian: “An international team of scientists claims to have found evidence for a slump in wellbeing among middle-aged chimpanzees and orangutans. The lull in happiness in the middle years, they say, is the great ape equivalent of the midlife crisis. The study has raised eyebrows among some scientists, but according to the authors, the findings suggest that the midlife crisis may have its roots in the biology humans share with our closest evolutionary cousins. "There's a common understanding that there's a dip in wellbeing in middle age, and that's been found in many datasets across human cultures," Alex Weiss, a psychologist at Edinburgh University, told the Guardian. "We took a step back and asked whether it's possible that instead of the midlife crisis being human-specific, and driven only by social factors, it reflects some evolved tendency for middle-aged individuals to have lower wellbeing." [Source: Ian Sample, The Guardian, November 19, 2012]

“The team from the US, Japan, Germany and the UK asked zookeepers, carers and others who worked with male and female apes of various ages to complete questionnaires on the animals. The forms included questions about each ape's mood, the enjoyment they gained from socialising, and their success at achieving certain goals. The final question asked how carers would feel about being the ape for a week. They scored their answers from one to seven. |=| “More than 500 apes were included in the study in three separate groups. The first two groups were chimpanzees, with the third made up of orangutans from Sumatra or Borneo. The animals came from zoos, sanctuaries and research centres in the US, Australia, Japan, Canada and Singapore. |=|

“When the researchers analysed the questionnaires, they found that wellbeing in the apes fell in middle age and climbed again as the animals moved into old age. In captivity, great apes often live to 50 or more. The nadir in the animals' wellbeing occurred, on average, at 28.3 and 27.2 years old for the chimpanzees, and 35.4 years old for the orangutans. |=| "In all three groups we find evidence that wellbeing is lowest in chimpanzees and orangutans at an age that roughly corresponds to midlife in humans," Weiss said. "On average, wellbeing scores are lowest when animals are around 30 years old." |=|

“The team explains that the temporary fall in ape wellbeing may result from more depressed apes dying younger, or through age-related changes in the brain that are mirrored in humans. Weiss conceded that, unlike men, great apes are not known to pursue radical and often disastrous lifestyle changes in middle age. |=|

“Robin Dunbar, professor of evolutionary psychology at Oxford University, was dubious about the findings. "What can produce a sense of wellbeing or contentedness that varies across the lifespan like this? It's hard to see anything in an ape's life that would have that sort of pattern, that they would cogitate about. They're not particularly good at seeing far ahead into the future, that's one of the big differences between them and us." Alexandra Freund, professor of psychology at the University of Zurich, was also sceptical. She said the concept of a midlife crisis was shaky even in humans. "In my reading of the literature, there is no evidence for the midlife crisis. If there's any indication of decline in emotional or subjective wellbeing it is very small and in many studies, it's not there at all." |=|

“But Weiss believes the findings could point to a deeper understanding of the emotional crisis some men may experience. "If we want to find the answer as to what's going on with the midlife crisis, we should look at what is similar in middle-aged humans, chimps and orangutans," he said.” |=|

What Makes Humans Unique from Other Animals

Melissa Hogenboom wrote for the BBC: “In recent years, many traits once believed to be uniquely human, from morality to culture, have been found in the animal kingdom. So, what exactly makes us special? The list might be smaller than it once was, but there are some traits of ours that no other creature on Earth can match. Ever since we learned to write, we have documented how special we are. The philosopher Aristotle marked out our differences over 2,000 years ago. We are "rational animals" pursuing knowledge for its own sake. We live by art and reasoning, he wrote. Much of what he said stills stands. [Source: Melissa Hogenboom, BBC, July 6, 2015 |::|]

“Yes, we see the roots of many behaviours once considered uniquely human in our closest relatives, chimpanzees and bonobos. But we are the only ones who peer into their world and write books about it."Obviously we have similarities. We have similarities with everything else in nature; it would be astonishing if we didn't. But we've got to look at the differences," says Ian Tattersall, a paleoanthropologist at the American Museum of Natural History in New York, US. |::|

“Humans and chimpanzees diverged from our common ancestor more than six million years ago. Fossil evidence points to the ways which we have gradually changed. We left the trees, started walking and began to live in larger groups. And then our brains got bigger. Physically we are another primate, but our bigger brains are unusual. We don't know exactly what led to our brains becoming the size they are today, but we seem to owe our complex reasoning abilities to it. |::|

“Evidence in the form of stone tools suggests that for about 100,000 years our technology was very similar to the Neanderthals. But 80,000 years ago something changed. "The Neanderthals had an impressive but basically routine material record for a hominin. Once H. sapiens started behaving in a strange, [more sophisticated] way, all hell broke loose and change became the norm," Tattersall says. We started to produce superior cultural and technological artefacts. Our stone tools became more intricate. |::|

“That our rapidly expanding technology has allowed us all to become instant publishers means we can share such information at the touch of a button. And this transmission of ideas and technology helps us in our quest to uncover even more about ourselves. That is, we use language to continue ideas that others put forward. Of course, we pass on the good and the bad. The technology that defines us can also destroy worlds. Take murder. Humans aren't the only species that kill each other. We're not even the only species that fight wars. But our intelligence and social prowess mean we can do so on an unprecedented scale.” |::|

Art and Abstraction Set Humans Apart from Animals?

Melissa Hogenboom wrote for the BBC: “One study proposes that our technological innovation was key for our migration out of Africa. We started to assign symbolic values to objects such as geometrical designs on plaques and cave art. There is little evidence that any other hominins made any kind of art. One example, which was possibly made by Neanderthals, was hailed as proof they had similar levels of abstract thought. However, it is a simple etching and some question whether Neanderthals made it at all. The symbols made by H. sapiens are clearly more advanced. We had also been around for 100,000 years before symbolic objects appeared so what happened? [Source: Melissa Hogenboom, BBC, July 6, 2015 |::|]

“Somehow, our language-learning abilities were gradually "switched on", Tattersall argues. In the same way that early birds developed feathers before they could fly, we had the mental tools for complex language before we developed it. We started with language-like symbols as a way to represent the world around us, he says. For example, before you say a word, your brain first has to have a symbolic representation of what it means. These mental symbols eventually led to language in all its complexity and the ability to process information is the main reason we are the only hominin still alive, Tattersall argues. It's not clear exactly when speech evolved, or how. But it seems likely that it was partly driven by another uniquely human trait: our superior social skills. |::|

“We are unique in the level of abstractness with which we can reason about others' mental states This tells us something profound about ourselves. While we are not the only creatures who understand that others have intentions and goals, "we are certainly unique in the level of abstractness with which we can reason about others' mental states", says Katja Karg, also of the Max Planck Institute for Evolutionary Anthropology. |::|

“When you pull together our unparalleled language skills, our ability to infer others' mental states and our instinct for cooperation, you have something unprecedented. Us.Just look around you, Tomasello says, "we're chatting and doing an interview, they (chimps) are not." We have our advanced language skills to thank for that. We may see evidence of basic linguistic abilities in chimpanzees, but we are the only ones writing things down. |::|

“We tell stories, we dream, we imagine things about ourselves and others and we spend a great deal of time thinking about the future and analysing the past.There's more to it, Thomas Suddendorf, an evolutionary psychologist at the University of Queensland in Australia is keen to point out. We have a fundamental urge to link our minds together. "This allows us to take advantage of others' experiences, reflections and imaginings to prudently guide our own behaviour. "We link our scenario-building minds into larger networks of knowledge." This in turn helps us to accumulate information through many generations.” |::|

Mind Reading Sets Humans Apart from Animals?

Melissa Hogenboom wrote for the BBC: “The fact that our nearest relatives share too simply shows that it is an ancient trait. It was already present in the messy branch of early humans that led to us, but none of these other species were as hyper cooperative as we are today. These cooperative skills are closely tied to our incredible mind reading skills. We understand what others think based upon our knowledge of the world, but we also understand what others cannot know. The Sally-Anne task is a simple way to test young children's ability to do this. [Source: Melissa Hogenboom, BBC, July 6, 2015 |::|]

“The child witnesses a doll called Sally putting a marble in a basket in full view of another doll, Anne. When Sally leaves the room, Anne moves the marble to a box. Sally then comes back, and the experimenter asks the child where Sally will look for the marble. Because Sally didn't see Anne move the marble, she will have a "false belief" that the marble is still in the basket. Most 4-year-olds can grasp this, and say that Sally will look in the basket. They know the marble is not there, but they also understand that Sally is missing the key bit of information. |::|

“Chimps can knowingly deceive others, so they understand the world view of others to some extent. However, they cannot understand others' false beliefs. In a chimpanzee version of the Sally-Anne task, researchers found that they understand when a competitor is ignorant of the location of food, but not when they have been misinformed. Tomasello puts it like this: chimpanzees know what others know and what others can see, but not what others believe.” |::|

Humans Outlive Apes Because of Genetic Change?

Genetic modifications that appear to allow humans to live longer than other primates may have its origin in a more carnivorous diet because, some scholars argue, these changes may also promote brain development and make us less vulnerable to dementia, aging and diseases such as cancer and heart disease. Charles Q Choi wrote in Livescience: “Chimpanzees and great apes are genetically similar to humans, yet they rarely live for more than 50 years. Although the average human lifespan has doubled in the last 200 years – due largely to decreased infant mortality related to advances in diet, environment and medicine – even without these improvements, people living in high mortality hunter-forager lifestyles still have twice the life expectancy at birth as wild chimpanzees do. [Source: Charles Q Choi,, December 2009 \=/]

“These key differences in lifespan may be due to genes that humans evolved to adjust better to meat-rich diets, biologist Caleb Finch at the University of Southern California in Los Angeles suggested. The oldest known stone tools manufactured by the ancestors of modern humans, which date back some 2.6 million years, apparently helped butcher animal bones. As our forerunners evolved, they became better at capturing and digesting meat, a valuable, high-energy food, by increasing brain and body size and reducing gut size.” Finch his findings in the December 2009 issue of Proceedings of the National Academy of Sciences. \=/

“Over time, eating red meat, particularly raw flesh infected with parasites in the era before cooking, stimulates chronic inflammation, Finch explained. In response, humans apparently evolved unique variants in a cholesterol-transporting gene, apolipoprotein E, which regulates chronic inflammation as well as many aspects of aging in the brain and arteries. \=/

“One variant found in all modern human populations, known as ApoE3, emerged roughly 250,000 years ago, “just before the final stage of evolution of Homo sapiens in Africa,” Finch explained. ApoE3 lowers the risk of most aging diseases, specifically heart disease and Alzheimer’s, and is linked with an increased lifespan. “I suggest that it arose to lower the risk of degenerative disease from the high-fat meat diet they consumed,” Finch told LiveScience. “Another benefit is that it promoted brain development.” \=/

“Curiously, another more ancient variant of apolipoprotein E found in a lesser degree in all human populations is ApoE4, which is linked with high cholesterol, shortened lifespan and degeneration of the arteries and brain. “The puzzle is, if ApoE4 is so bad, why is it still present?” Finch asked. “It might have some protective effects under some circumstances. A little bit of data suggests that with hepatitis C, you have less liver damage if you have ApoE4.”“ /=\

Image Sources: Wikimedia Commons

Text Sources: National Geographic, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Nature, Scientific American. Live Science, Discover magazine, Discovery News, Ancient Foods ; Times of London, Natural History magazine, Archaeology magazine, The New Yorker, Time, Newsweek, BBC, The Guardian, Reuters, AP, AFP and various books and other publications.

Last updated September 2018

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