Monday, March 5, 2012

Even young kids figure out what you like from what you choose

We figure out a lot about the people around us from what they do rather than what they say.  The actions people take say a lot about what they truly want, while the statements people make may not reflect what they truly believe.  That is why we prefer people who ‘walk the walk’ over those who ‘talk the talk,’ and we push people to ‘put their money where their mouth is.’

What allows us to figure out what people really like from their actions?  When do we learn to do that?

This question was taken up in a paper by Tamar Kushnir, Fei Xu, and Henry Wellman in an August, 2010 paper in Psychological Science. 

They start with a simple example.  You can figure out whether people’s actions tell you what they like when there is a clear choice in the world and people do something systematic in that case.  Imagine you go to a candy store and all they have is chocolate.  You bring your friend to the store and tell her to buy something.  She buys chocolate.  It is hard to say from this choice that she really likes chocolate.  All there was in the whole store was chocolate.  Maybe she prefers Gummi Worms, but they weren’t available.

But, what if you take your friend to a store that has chocolate on every aisle, but then there is also one display case with Gummi Worms.  Now, if she buys Gummi Worms, you can safely assume she really likes them.  After all, if she just grabbed something in the store by chance, she probably would have gotten chocolate.  The fact that she picked something rare in the store means that she must really like it.

Perhaps this isn’t so surprising, but Kushnir, Xu, and Wellman looked at whether 3- and 4-year-olds could reason in the same way.  They had children in the study look at a box of toys.  Some boxes only had one kind of toy in them (like soft baseballs).  Another box had two toys in it (like soft baseballs and soft basketballs).  A third box also had two types of toys, but there were mostly toys of one type and a few of the other (a lot of soft basketballs and just a few soft baseballs).

Now, the children watched as a puppet took five toys out of the box.  In each case, the puppet took five of one type of toy out of the box (say, soft baseballs).  Then, the puppet went away.  The child was shown three toys, the two from the boxes and a third that they had never seen before (like a green golf ball).  The puppet came back, and the child was asked to give the puppet the toy it liked best.

The children were quite smart about this.  When the box only had toys of one type, then the children gave the puppet each of the three toys about equally often.  That is, they seemed to realize that the puppet had no choice but to pick one type of toy, and so that didn’t tell them much about what the puppet really liked. 

When the box had two types of toys and there were many more of one type than the other and the puppet consistently picked the rare toy, then the children almost always gave the puppet the toy it had picked. 

When the box had the same amount of each kind of toy, then the children also gave the puppet the toy it had picked, but they did so a bit less consistently than when the toy was really rare.

This result (as well as the results of a follow-up study with 20-month-old infants in the same paper), suggest that humans are very good at figuring out what other people want just from what they do.

It is important that we have this ability from fairly early in life.  The psychologist Mike Tomasello has argued that humans are very good at passing along culture, because children are able to figure out why people are doing what they do from watching what people are doing.  As a result, children learn quickly how to perform actions that will allow them to achieve desirable goals. 

In addition, in order to figure out how to succeed in our social groups, we have to be able to predict what people will do in the future.  By using people’s actions as a guide to their thoughts and preferences, young children help to fit themselves into their network of caregivers and friends.