Imagine your neighbor has a dog that regularly escapes her yard. One day you see the dog escape and return it to her. She thanks you by giving you a piece of delicious home-made apple pie. This happens several days in a row. Then one day when you return the dog, there’s no pie, no thanks, and no explanation. Would you return the dog the next time it escapes?
You might be disinclined. But what if there had never been any reward? Wouldn’t returning her dog be the right thing to do?
Children as young as 14 months old will spontaneously help others for no reward. But a 1973 study of 3- to 5-year-olds found that although these kids would spontaneously draw pictures, if they were given a reward for drawing pictures, then later they wouldn’t make any drawings unless a reward was offered. Could offering a reward actually suppress the natural inclination to do good things?
Felix Warneken and Michael Thomasello placed 48 German toddlers averaging 20 months of age in a room (one at a time) with a parent and an experimenter who sat at a table in the corner, apparently doing an unrelated task like placing balls in a basket or clipping napkins together. The experimenter pretended to accidentally drop one of the objects on the floor, and reached for it while looking at the toddler, waiting up to 30 seconds for the toddler to help her by picking it up. Eight of the children refused to leave their parent, and ten didn’t complete the task, but 36 became reliable helpers, returning the object to the experimenter 5 times.
Of the 36, each time they helped out, 12 were given no reward or praise, 12 were thanked verbally, and 12 were rewarded with a cube they could use to activate a fun toy:
(Click on the image to see a very cute video of a toddler getting a reward)
Next, the children were tested to see if they would continue to help the experimenter without a reward. Since the 36 toddlers were very reliable helpers, the task was made a little more challenging. Before the experimenter dropped her object, the toddler was presented with an exciting new toy. He would have to leave this toy in order to help out — and no reward was given. This was repeated 9 times. Here’s a typical response from a toddler who received no reward previously:
In fact, nearly all of them were willing to help even when they had a new exciting toy to play with.
But the response from toddlers who had been rewarded previously was different:
When no rewards were offered, these children helped out only about 50 percent of the time. This graph displays the complete results of the study:
Children who had previously received rewards helped the experimenter significantly less often than either the group that received only praise or the group that received no praise.
Warneken and Tomasello conclude that rewarding children for altruistic behavior causes them to be less likely to be altruistic in the future, and these results certainly seem to be dramatic evidence of that conclusion. I’d only make one point in the toddlers’ favor: They had learned to play a game where both they and the experimenter had clear roles. The child helped out, and the experimenter gave him a prize. But halfway through the game, for these kids, the rules changed, and suddenly the experimenter wasn’t living up to her part of the bargain. Was it the reward, or the betrayal that caused the child’s behavior to change?
Warneken, F., & Tomasello, M. (2008). Extrinsic rewards undermine altruistic tendencies in 20-month-olds. Developmental Psychology, 44 (6), 1785-1788 DOI: 10.1037/a0013860