Who We Are: Part III

Animal Studies

This is the third installment in a series of postings in which I explore the growing mountain of scientific evidence that supports that human have, as a species, a cooperative nature.


Brian Hare, researcher for the Max Planck Institute for Evolutionary Anthropology, has been studying cooperative behavior in various animals for years. As a teenager Hare started studying the behavior of dogs in his parent’s basement. In his childhood experiments, which were the first of their kind, he indicated that the dogs were very good at following human non-verbal instructions. Later studies by other researchers supported Hare’s results showing that such attributes are genetically predetermined. Wolves lack this capacity, so the dog's abilities have been artificially selected by humans over the centuries through breeding.

At one point in his career Hare ended up at the Institute for Psychology and Genetics in Akademgorodok, Russia in which the researchers had been studying foxes since 1959. They were selectively breeding the foxes based on their degree of fear exhibited of humans. A control group was allowed to breed as usual while in the experimental group only those less fearful of humans were allowed to breed. Over time the behavior of the foxes in the experimental group changed. Those foxes took on dog like behaviors of barking and wagging their tails in the presence of humans as well as dog like physical appearance such as floppy ears, coats with differing degrees of markings, their skeletons became weaker, and their hormone balance changed. Along with all of this their social intelligence had begun to resemble the dogs in that they developed the ability to intuitively understand the directions of humans.

This trait of co-habitation and tolerance in dogs and the specially bred foxes lead to a hypothesis by Hare. He hypothesized that similar behavioral changes were prerequisites for the evolution of intelligence in humans. In other words, he hypothesized that our intelligence could not have evolved if we had not developed a prior practice of tolerance and the ability to cooperate with each other. He then proceeded to test his tolerance hypothesis. This required studying our closest relatives: the chimpanzees.

The Common Chimpanzees are known to be highly competitive and intolerant. For example, if a chimp of a lower rank attempts to eat from a bowl of food first then the higher ranking chimp will beat him and horde the food. Hare decided to test how far he could push this intolerance and find out what it would take for the chimps to cooperate with each other.

He set up an experiment with a bowl of food that could only be acquired by two chimps pulling on a rope together. If any chimpanzee alone tried to pull the rope it would fail so the only way to succeed would be for at least two chimps to cooperate. Time and time again they tried it individually and failed. But occasionally a few chimps would cooperate and successfully pull the rope together. It turned out that it was those few chimps that had already exhibited tolerance, such as eating together, that would be the ones that would cooperate with each other and would therefore succeed in the exercise.

When Hare studied Bonobos, a sub-species of chimpanzee, he found a very different story. Rather than a few tolerant members working together the bonobos naturally worked together to solve the problem. But true to their nature the bonobos, in a hedonistic style that would have made the free love of the 1960's seem puritanical, they would first have sex and would then cooperate in acquiring the food.

Bonobo Chimpanzees are interesting for many reasons. Being a sub-species of the chimpanzees they share at least a 98% genetic similarity with humans. Plus, their physical appearance is intriguing. The Bonobo have long head hair, pink lips, small ears and wide nostrils. In comparison to the Common Chimpanzee they have long legs, slim upper torso, and human-like breasts that are more prominent.
Hare has hypothesized that the point of separation of our ancestor from the chimps resulted from our ancestors purging the dominating and power hungry members in favor of tolerant and mild temperament members, which contrasts against the now discredited, though still widely accepted in pop culture, “killer-ape” theory. Hare and the other animal researchers have presented evidence that supports that what started our species in becoming human was not due to struggle and violence but mutual aid and cooperation.

In the next entry I will conclude this series with research that supports how natural selection can encourage the rise of a cooperative species.