Scarcity: Why Having Too Little Means So Much

by Sendhil Mullainathan

Using these tasks, we found that farmers performed much worse before harvest than after harvest. The same farmer fared worse on fluid intelligence and executive control when he was poor (preharvest) than when he was rich (postharvest). Much like the subjects at the mall, the same person looked less intelligent and more impulsive when he was poor. Yet in this case it was not us who triggered scarcity-related thoughts or even tried to bring them to the surface. These thoughts were there naturally when the farmers were poor (the harvest money dissipated to a small amount) but not when they were rich (still flush with cash from the harvest). And again the magnitudes were large. The postharvest farmers got about 25 percent more items correct on Raven’s. Put in IQ terms, as in the earlier mall study, this would correspond to about 9 or 10 IQ points. Not as big a gap as at the mall, but that is to be expected. After all, here we hadn’t induced them to think about money. We simply measured their mental state at an arbitrarily selected point in time, their latent tendency to have their bandwidth taxed by scarcity. On the executive control task, they were 11 percent slower in responding and made 15 percent more errors while poor, quite comparable to the mall study. Had we met a farmer when he was poor, we would have been tempted to attribute his limited capacity to a personal trait. But we know from our study that his limitation has little to do with his genuine capacity as a person...