I just started reading Your Erroneous Zones by Wayne Dyer, and the author has this to say about intelligence and happiness:
> Taking charge of yourself involves putting to rest some very prevalent myths. At the top of the list is the notion that intelligence is measured by your ability to solve complex problems; to read, write and compute at certain levels; and to resolve abstract equations quickly. This vision of intelligence predicates formal education and bookish excellence as the true measures of self-fulfillment. It encourages a kind of intellectual snobbery that has brought with it some demoralizing results. We have come to believe that someone who has more educational merit badges, who is a whiz at some form of scholastic discipline (math, science, a huge vocabulary, a memory for superfluous facts, a fast reader) is “intelligent.” Yet mental hospitals are clogged with patients who have all of the properly lettered credentials—as well as many who don’t. A truer barometer of intelligence is an effective, happy life lived each day and each present moment of every day. If you are happy, if you live each moment for everything it’s worth, then you are an intelligent person. Problem solving is a useful adjunct to your happiness, but if you know that given your inability to resolve a particular concern you can still choose happiness for yourself, or at a minimum refuse to choose unhappiness, then you are intelligent.