He told BBC news that it was evidence for an already observed phenomenon called "motivational crowding out, where paying an individual to do a task which they had already planned to do free of charge, could lead people to do this less".
However, Prof Bowles said that "most of the goods and services that we need that make our lives possible and beautiful are not like shirts".
"For these things, exchanging tokens could never work, which is why humans would never have become the co-operative species we are unless we had developed ethical and other regarding preferences."
goodwill trips me out.. waaaay more better stuff than starvation army of homophobes and pedophiles from what I'm smelling at those dumps
I remember reading years ago about a tribe that dealt in favors, that is when you did something for someone, they owed you in return. This society had taken this concept to a much more complex level, however, because families and elders kept track of these details, sometimes over generations. There were complex rules as to how these details were sorted out.
It has its limits, however. In any materially complex society, straight exchange rapidly becomes impossible, finding someone who has exactly what you want and wants exactly what you have available becomes pretty sketchy.
Along the lines of the experiment's change with larger groups, money/tokens make complex societies possible. If you buy a shirt, portions of that value move back to the farmer who grew the cotton, the person who made the buttons, who sewed the shirt, who created the sewing machines, who transported the shirt... etc. Imagine a complex item like car or home, with thousands or hundreds of thousands of people indirectly involved.
The whole issue of dealing in favors, recompense for those favors and the accompanying dynamics is not lost on a certain starship captain most of us know: