Materialism and the behaviors that go with it – desiring and buying brand-name clothes and luxury items – are symptoms of insecurity and a coping strategy used to alleviate feelings of self-doubt or bolster a poor self-image. But if what [we] are really seeking is greater happiness and fulfillment, materialism is a terrible coping method. At best it provides only short-term relief; in the long run it is likely to deepen feelings of insecurity.
From Christine Carter in Raising Happiness, referencing research in The High Price of Materialism
If you read Raising Happiness (and if you are a new parent, I recommend it), skip the first chapter, because it will put you off. The other chapters are very good, and cover key Positive Psychology research.