Happiness is a skill that can be learned.

It has long been assumed that economic prosperity brings happiness. However, the evidence is to the contrary. Economic growth in developed countries has gone hand-inhand with a rise in mental and behavioural disorders, family breakdown, social exclusion and diminished social trust. In China, for example, a 2009 study by German sociologists showed that the lifting of hundreds of millions of people out of poverty in the 1990s has been accompanied by an alarming decrease in life satisfaction at every level of income, in both rural and urban areas.
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Happiness is a skill that can be learned.

from
Happiness breeds prosperity Nature, by F. Huppert
http://www.nature.com/nature/journal/v464/n7293/pdf/4641275a.pdf