For example, when asked to write twenty statements beginning with the words “I am …,” Americans are likely to list their own internal psychological c… - Jonathan Haidt

People would be happier, and in the long run wealthier, if they bought basic, functional appliances, automobiles, and wristwatches, and invested the money they saved for future consumption; yet, Americans in particular spend almost everything they have — and sometimes more — on goods for present consumption, often paying a large premium for designer names and superfluous features.

Does helping others really confer happiness or prosperity on the helper? I know of no evidence showing that altruists gain money from their altruism, but the evidence suggests that they often gain happiness. People who do volunteer work are happier and healthier than those who don’t; but, as always, we have to contend with the problem of reverse correlation: Congenitally happy people are just plain nicer to begin with,24 so their volunteer work may be a consequence of their happiness, not a cause. The happiness-as-cause hypothesis received direct support when the psychologist Alice Isen25 went around Philadelphia leaving dimes in pay phones. The people who used those phones and found the dimes were then more likely to help a person who dropped a stack of papers (carefully timed to coincide with the phone caller’s exit), compared with people who used phones that had empty coin-return slots. Isen has done more random acts of kindness than any other psychologist: She has distributed cookies, bags of candy, and packs of stationery; she has manipulated the outcome of video games (to let people win); and she has shown people happy pictures, always with the same finding: Happy people are kinder and more helpful than those in the control group.

We should not expect individuals to produce good, open-minded, truth-seeking reasoning, particularly when self-interest or reputational concerns are in play. But if you put individuals together in the right way, such that some individuals can use their reasoning powers to disconfirm the claims of others, and all individuals feel some common bond or shared fate that allows them to interact civilly, you can create a group that ends up producing good reasoning as an emergent property of the social system. This is why it's so important to have intellectual and ideological diversity within any group or institution whose goal is to find truth (such as an intelligence agency or a community of scientists) or to produce good public policy (such as a legislature or advisory board).