1.    Cooperation: We inherited it from our ancestors

http://www.nytimes.com/2006/03/03/science/03chimp.html

Research at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany suggests that chimpanzees, like humans, cooperate. As reported in the New York Times of March 3, 2006, by Carl Zimmer, in one set of experiments, a chimpanzee alone in a cage saw food outside of her/his cage, but to obtain the food had to pull on two ropes. When the ropes were too widely separated from each other for one chimpanzee to reach alone, the chimpanzee would open a door and seek out another chimpanzee for help.

Furthermore, the chimpanzee remembered which of their fellows were better helpers, and tended to choose them when the same situation occurred. Most interesting was that the researchers found chimpanzees who were agreeable to helping even without receiving a direct reward for that help. Similarly, the article also reports another set of studies in which chimpanzees displayed other altruistic behaviors. 

The author concludes by stating that:

Chimpanzees are the closest living relatives to humans, sharing a common ancestor that lived roughly six million years ago. If their nature is as cooperative as these studies suggest, then scientists say they may have inherited this ability from that common ancestor.

These studies seem to support optimism as to whether students can successfully collaborate with one another. At the same time, it raises the question of why we humans cannot cooperate with our fellow animals by not putting them in cages, eating them, and wearing their skin and fur.

2.    Players without Coaches

http://sports.espn.go.com/nba/news/story?id=2271143

Cooperative learning gives students some time without immediate supervision by teachers. This article from the ESPN website describes how athletes, even very well-paid professional athletes in the National Basketball Association (North America), can sometimes similarly benefit from time without their coaches.

Here are a couple quotes from the players about the benefits of sometimes practicing without their coaches:

There are times when the coaches kind of seem like they're always on the players and players just stop responding just because they feel as if they can do nothing right. It kind of messes with your head a bit. So when you hear it from the guys -- that our agenda is to win and we're trying to help each other and be there for each other -- it relaxes you a little bit.

[S]ometimes players can hold back and not say what they really want to say. But once you're amongst the guys, you can get everything out.

Perhaps the same benefits apply when students sometimes practice without their teachers.