Monkey generosity: No strings attached

Jul 14, 2010 by Chris Barncard

(PhysOrg.com) -- Among monkeys that split child care responsibilities, sharing extends to dinnertime, but grudges do not, according to research published July 14 in Proceedings of the Royal Society B.

Pairs of adult cottontop tamarins will share food, upholding the cooperative breeding hypothesis that expects members of species that share the burden for raising young are also motivated to help each other in other ways.

"A big issue in terms of evolution has been how humans — or any social animals — developed altruism," says Charles Snowdon, a psychology professor at the University of Wisconsin-Madison. "The argument is that altruistic animals are either helping kin or helping in expectation of future return."

In the case of cottontop tamarins, Snowdon and former psychology graduate student Katherine Cronin had earlier found an absence of the food-donating altruism that had been seen in other in cooperatively breeding species such as humans and marmosets. But Cronin and research assistant Kori Schroeder developed a simpler series of tasks that measured how the small monkeys' propensity for sharing changed over time.

Adult tamarin pairs — "Like human married couples, not related but together for a long time," Snowdon says — were placed in a situation in which one of them appeared to be either donating food to or withholding food from the other.

The researchers then turned the tables, giving the recipient tamarin real control over a drawer that could provide a piece of a favorite food to its (recently generous or miserly) partner without any reward for itself.

"Initially, the tamarins were put off by having been denied rewards by their partner," Cronin says. "They reacted by providing less, in turn. This reaction didn't last long, however."

Over the course of five minutes, the researchers found, the study tamarins were feeding their mate the same amount of food no matter their recent sharing history.

"Because the tamarins form lifelong bonds with their partners, it makes sense that they don't hold grudges for too long," Cronin says. "They'll make a more successful pair if they help each other out."

"What that's suggesting is it's not direct reciprocity," Snowdon says. "What the tamarins are showing is something akin to , and it's independent of whether they were treated well or poorly by their mate."

Explore further: Male monkey filmed caring for dying mate (w/ Video)

Related Stories

Veterinarians adapt human tests for monkeys

Aug 07, 2008

A medical test developed to detect an overload of iron in humans has recently been adapted to screen for the condition in some distant relatives: diminutive monkeys from South America, according to veterinarians ...

Chimpanzees help each other on request but not voluntarily

Oct 14, 2009

The evolution of altruism has long puzzled researchers and has mainly been explained previously from ultimate perspectives—I will help you now because I expect there to be some long-term benefit to me. However, ...

Like humans, monkey see, monkey plan, monkey do

Dec 06, 2007

How many times a day do you grab objects such as a pencil or a cup? We perform these tasks without thinking, however the motor planning necessary to grasp an object is quite complex. The way human adults grasp ...

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

13 hours ago

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 0

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Plants with dormant seeds give rise to more species

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...