Are conservatives more optimistic?

From today's WSJ Arthur Brooks defends conservatism. Here is the argument:

Conservatives are relatively untroubled by inequality, and unsupportive of government income redistribution, because they believe the American economy provides private opportunities to succeed. Liberals are far more pessimistic than conservatives about the possibility of a better future for Americans of modest means.

And here goes the conclusion:

One thing that is clear, however, is that conservatives' lack of anxiety about income inequality -- and perhaps even their opposition to redistributive government policies -- is evidence of a light heart, not a hard one.

I am a little bit skeptical about it. I'd like to see the data on charity giving among conservatives and liberals before jumping to the conclusion.