Money can't buy happiness, said the humanist psychologists of the 1960s.
They argued that pursuing goals based on "extrinsic rewards" - the approval of other people - and "having" instead of "being" distract us from the meaningful aspects of life, and cause psychological distress. But things have changed. Today, cognitive-behavioural therapists (CBT) believe that the setting and pursuit of goals, regardless of what they are, is good for us.
The problem with trying to resolve the debate scientifically is that most research has focused on the simpler question of whether material success makes us happy. There is indeed some relationship between how well off you are and how happy you are, but once the basic human needs of food, shelter and other fundamental wants are met, the link between how much you have, and how content you are, gets fuzzier.
If you don't want much more than the basics, for example, then having a bit extra will probably make you feel quite content. But if you aspire to great wealth and fall short, then you may feel a failure. In other words, it's not what you have which is important, but how much it measures up against what you want or expect.
So are financial goals responsible for much human discontent? Should we instead aim for a kind of Zen state of no desire? A group led by economic psychologist Daniel Kahneman attempted to answer this question a few years ago. In 1976, 12,894 freshmen drawn from 21 academically selective universities in the United States rated the importance of being wealthy.
When they were followed up 20 years later, the researchers found that the students who had had the most ambitious financial goals were less satisfied with their lives than those with modest aspirations. No surprise for the die-hard humanists there.
However, these results do not support either the humanists or the cognitive behaviourists. For example, the humanists do not agree that the more you earn, the happier you become, a notion which the research seems to support.
But what doesn't fit with current CBT thinking is that students with high goals were no happier when they did make their money than those who considered financial gains unimportant. It would have expected respondents who hit their high financial targets to be more satisfied than those with an equivalent income but less ambition.
A resolution may come from another recent study by psychologists Charles Carver and Eryn Baird of the University of Miami, who suggests it's not what you want that matters, but why you want it. They say there are two types of desire: intrinsic and extrinsic. Intrinsic motivation means we want things for personal reasons. Extrinsic or controlling motivation comes from outside forces, such as the law, or a desire to be liked and approved of by one's peers.
For example, people might want to improve the environment because of their political beliefs or because they enjoy being an activist (intrinsic reasons). But they might also do it because they believe it will earn them respect (an extrinsic reason).
Similar reasoning applies to financial success. We could aspire to it because it might increase our popularity; but we might also want high-income jobs because they're likely to be more fun.
Dr Raj Persaud is Gresham professor for public understanding of psychiatry, and director of the Centre for Public Engagement, King's College London.
His latest book is The Motivated Mind (Bantam Press). Email: firstname.lastname@example.org