Iowa State University

Inside Iowa State
Oct. 10, 1997

A revealing game of marbles

by Michelle Johnson

Twelve marbles, three containers and a couple of bucks. Sounds like something played in a back alley somewhere. But to Camilo Garcia, it's an exercise in understanding a complex psychological process.

Garcia, assistant professor of human development and family studies, researches how people understand interdependence -- the concept of how people's actions and the outcomes of those actions affect one another. To determine how people grasp the idea of inter-dependence, Garcia conducts an experimental task in competition vs. cooperation. He designed the task with UCLA anthropologist Kaveh Ehsani.

The task places two individuals in a room together. They are shown three containers, each holding four marbles. The maximum capacity of each container is eight marbles. The individuals are asked how many containers can be filled given the number of marbles being used. The answer, of course, is only one.

"Every participant over the age of 7 responds correctly to that question," said Garcia. "But the information is almost immediately discarded once the task gets under way."

Each participant is assigned one container and told that the "owner or owners" of the container that is filled first will receive $2. The third container is placed between the two participants and used as a common container. The participants are allowed to transfer the marbles to or from any container they choose. They have four attempts to fill a container. The task is computerized and communication between participants is not allowed.

Will the participants figure out that cooperation is the only way to fill a container? Garcia's past experience indicates that most do, but for some, it's a struggle.

There are three levels of under-standing inter-dependence: individualistic, competitive, and cooperative, according to Garcia. Whether participants compete or cooperate depends upon the level of understanding they reach.

Individualistic people see only their containers and try to fill them first. Competitive people see both their containers and the other participants'. The competitors try not only to fill their own, but to keep others from filling theirs.

Why is cooperation the last method chosen for the individualistic and competitive types? What is it that causes them to focus on their containers or prevent others from filling theirs when there is nothing to gain?

One theory is that people gather from the instructions that filling the middle container means sacrificing half the reward -- they each get only one dollar. In their minds, cooperation means losing, Garcia said. For some, that just won't do.

In a study of UCLA pre-medical students who were given 10 attempts each to fill their containers, Garcia watched as participants exchanged the same marble 20 times.

Garcia has conducted research in the United States, Mexico and Europe. The results have shown some cultural differences. While in some cultures, cooperation clearly isn't the method of choice, in others, it is the only way, he said.

In a study of 30 Mexican workers, each set of participants asked if the middle container could be filled more than once.

A group of young, rural Mexican girls exchanged marbles the same as the UCLA pre-med students. The only difference was that each girl was trying to give to, not take from, the other. Theirs was the only study in which individuals considered the option of filling the other's container.

White Anglo-Saxon men and women exhibited the most competitiveness.

So far, Garcia has compared only individuals of the same sex and same ethnicity. He plans to expand the study to look at different cultures and gender.

"We can all be good mathematicians and engineers, but very inefficient in social interaction" Garcia said. "Social interaction requires a lot more thinking."

According to Garcia, every social interaction requires cooperation and an awareness of interdependence: employer and employee, parent and child, husband and wife, roommates, and teacher and student.

"A good professor explains things thoroughly and accurately," Garcia said. "A great professor is the one who clearly acknowledges that the other half of the equation lies in the students."

Cooperation. It's possible. And, as far as Garcia is concerned, it's worth destroying our illusions that one alone can win in situations of interdependence.

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