Finding Friends In Primate Places

Humans aren't the only ones who like companionship.

Just like the human versions, nonhuman primates are social creatures. They clean each other, cooperate with each other, help each other with eating. This year, a few studies added even more to what we know about primate relationships, and indeed, science has been investigating this topic for quite some time. In 1991, the journal Lab Animal Science published a study on the topic titled “Social interaction in nonhuman primates: an underlying theme for primate research.” And then more than a decade later, a 2002 paper discussed the use of the “f-word” (aka friendship) in primatology. In the paper, primatologist Joan B. Silk, writes that using friendship to describe primate relationships is a possible “backlash against what some researchers see as a narrow-minded preoccupation with the negative aspects of animal behavior, such as competition, conflict, manipulation, coercion, and deception.” Instead of all that negativity, some scientists are looking at the more positive side of primate behavior. Despite critics of referring to these relationships as bonafide friendships, humans still turn to our fuzzy cousins as targets upon which to foist our friendly feelings.

Here are some of our favorite studies of primate companions:

Vervet Monkeys Cooperate

It can be hard enough to get grown adults to work together. But vervet monkeys are putting us human primates to shame. In a study back in March, researchers had these monkeys play a game called forbidden circle–at least that’s what the researchers called it. This game presented a social dilemma, which required coordination between dominant and lesser-ranking monkeys. The lesser-ranking female was trained to open a container of food, but she would only do so when every dominant monkey was no longer within the so-called forbidden circle. After trial and error, the dominants learned to cooperate through individual learning and patience, benefitting dominant and lesser-ranking monkeys alike.

The Networks Of Rhesus Macaques

Perhaps similar to the human world, animals see very fundamental benefits of maintaining a strong network of social ties. One such benefit is better odds of your progeny surviving—and those offspring are likely to be pretty social themselves. A study from January, published in Nature Scientific Reports analyzed two years of rhesus macaque observations as well as 75 years of pedigree data, and genetic information. Using that information, the research team built network maps, and found that social monkeys also had a large number of friends-of-friends, while loners were “sort of the dorks.”

Friends Before Family For Crested Macaques

When it comes to a dangerous situation, crested macaques look to their friends for guidance more readily than their family members. Researchers determined this by measuring how quickly macaque would follow the gaze of another. In the crested macaques, test subjects tended to react quicker to the gazes of friends with whom they had a strong social bond. This social bond was measured by recording how much time the macaques spent together. While following another’s gaze may seem insignificant, it’s a behavior that is especially important for getting out of precarious predicaments, or when trying to find food–both situations that necessary for survival.

A Friendly Baboon Is a Calm Baboon

Stressed-out baboons probably just need a few friends to help calm them down. A research team studied observation records of 45 female baboons from 2001 to 2007, and as a result found that those with more friends had lower stress hormone levels. So if you’re a female baboon, and you want to make said-friends, there’s some grunting involved, but it also comes down to being just plain nice. The researchers from the University of Pennsylvania looked at how often the female baboons were alone, how often they touched other females, and how often they were aggressive. Scientists also considered how often the female baboons were approached by others and how often they grunted when approaching other females (a sign of good will, unlike in human social behavior). These behaviors helped to classify the female baboons as nice, aloof, or loner. The nice baboons had more close bonds, and thus had lower stress. Aloof females still had social ties, but less. And the loner baboons had significantly less “friends,” and thus significantly higher stress hormone levels.

Social Networking Squirrel Monkeys

Earlier this year, a group of scientists observed squirrel monkeys’ ability to open an artificial fruit. They used this taske in order to analyze the diffusion of socially-learned foraging techniques. In other words, how monkeys with friends are better at catching on to the latest trend. The alpha male got a little help from researchers, who trained them how to open the hatch or pivot open the artificial fruits to get treats housed inside. The researchers found that the monkeys with the strongest social ties picked up the new opening method much more quickly than those who were more peripheral.

Lemur Thieves Thrive In Packs

Brown, black, mongoose, ring-tailed, coquerel’s sifakas and ruffed lemurs all participated in this study. Researchers looked specifically at the size of the lemurs’ social groups, with regards to how they helped to predict the cognitive skills. Or, as Scientific American put it, “highly social lemurs are better thieves.” The lemur species that usually lived in a large, 15-member group had significantly better social cognition than other species, which lived in groups of about five. Ten lemurs of each of the six species were given a simple task: take food from researchers. More social lemurs were more likely to steal food from the researcher that wasn’t paying attention. However, don’t be too quick to assume the more friends, a smarter lemur makes.”Being socially savvy doesn’t make you brainy in every domain,” study author Evan MacLeans said in a statement.