How materialism makes us sad

Two quotes of note from the article and its sources:
- A study at Berkeley University, quoted by Music ... "The higher up the social-class ranking people are, the less pro-social, charitable and empathetically they behaved " consistently those who were less rich showed more empathy and more of a wish to help others.", and
- "Those with more materialistic values consistently have worse relationships, with more conflict," Music writes. "This is significant if the perceived shift towards more materialistic values in the west is accurate."
http://www.theatlantic.com/business/archive/2013/04/money-buys-happiness-and-you-can-never-have-too-much-new-research-says/275380/
(Whether this reflects causation or not is left as an exercise for the reader.)