Marginal utility can be measured. According to new research out of Wolfram Schultz’s lab, poor people are much quicker learners than rich people when playing a Pavlovian paradigm for small amounts of money. (Poor people took about 12 trials to figure out the game, while rich people took about 35 trials.) This behavior was then confirmed with fMRI. Sure enough, rich people demonstrated less dopaminergic midbrain activity than poor people in response to the experimental paradigm. They were bored by the pocket change. Here’s the abstract:
A basic tenet of microeconomics suggests that the subjective value of financial gains decreases with increasing assets of individuals (“marginal utility”). Using concepts from learning theory and microeconomics, we assessed the capacity of financial rewards to elicit behavioral and neuronal changes during reward-predictive learning in participants with different financial backgrounds. Behavioral learning speed during both acquisition and extinction correlated negatively with the assets of the participants, irrespective of education and age. Correspondingly, response changes in midbrain and striatum measured with functional magnetic resonance imaging were slower during both acquisition and extinction with increasing assets and income of the participants. By contrast, asymptotic magnitudes of behavioral and neuronal responses after learning were unrelated to personal finances. The inverse relationship of behavioral and neuronal learning speed with personal finances is compatible with the general concept of decreasing marginal utility with increasing wealth.