"Show me the money," demanded Cuba Gooding Jr., in the movie "Jerry McGuire." He meant pay me the money, of course, but it turns out that merely showing it to people can change their behavior.

Kathleen Vohs, assistant professor of marketing at the University of Minnesota, and colleagues, conducted a series of nine experiments in which people were asked to do puzzles or other tasks and the behavior of people exposed to money was compared to others who were not prompted to think about it.

The two groups acted differently, the researchers report in Friday's issue of the journal Science.

"The mere presence of money changes people," Vohs said. "The effect can be negative, it can be positive. Exposure to money, or the concept of money, elevates a sense of self-sufficiency," and can make people less social.

For example, she said, a student with little money who wants to move to a new apartment gets a bunch of friends together and they have a few laughs along the way.

But once they get a good job they hire a mover. That may be more efficient, but they lose out on some personal moments, she explained in a telephone interview.

"The underlying idea is that at some point early on in human evolution everyone probably needed someone else to help them achieve their goals," whether building a home or catching food. Eventually systems of exchange came along, and then money, which could be exchanged for things, allowing people to pursue their own aims without the aid of others. So, over time, people with money didn't need other people so much.

In one of the experiments, 52 University of Minnesota students were divided into groups and asked to make sentences out of a scrambled group of words. For one group the sentence turned out to be "a high-paying salary" while others got "it is cold outside."

Then they were asked to arrange a set of discs into a square and told they could ask for help if they needed it. Some of those who had made sentences not mentioning money were placed so they could see a stack of Monopoly money.

The students who had unscrambled the sentence about money worked on the puzzle an average of 5.2 minutes before asking for help. Those who had made the neutral sentence but could see the play money worked on it an average of 5.1 minutes.

But students who had no money-related prompt turned to others for help sooner, they worked just over 3 minutes before asking for help.

In another experiment 44 students at Florida State University were each given $2 in quarters — which they were told was leftover from a previous experiment — and asked to unscramble sentences that divided them into two groups, one that was reminded of money by the sentence and others that were not.

When they left, the researcher noted that there was a box by the door for donations for needy students if they wanted to chip in, but they didn't have to.

On average, students who had read neutral sentences donated $1.34 while those whose sentences reminded them of money kept more for themselves, giving an average of just 77 cents.

In another test, 61 students at the University of British Columbia sat at desks to fill out questionnaires. Some desks faced a poster showing money, some saw a poster of flowers and others saw a seascape.

They were then asked to choose between group or individual recreational activities, such as a dinner for four or individual cooking lessons. Those who had seen the money poster were more likely to pick individual activities than those looking at the other posters.

The experiments indicate that even quite trivial exposure to money changes peoples' goals and behavior, Carole B. Burgoyne and Stephen E. G. Lee of the University of Exeter in England said in a commentary on the paper.

"Subjects exposed to the idea of money subsequently show more self-reliant but also a more self-centered approach to problem solving that subjects exposed to neutral concepts," said Lee and Burgoyne, who were not part of Vohs research team.

Vohs research was funded by the Social Sciences and Humanities Research Council of Canada and the Canada Research Chair Council.