What the MIT researchers did find, however, was that conservatives give more to religious organizations, such as their own churches, and liberals more to secular recipients. Conservatives may give more overall, MIT says, but that's because they tend to be richer, so they have more money to give and get a larger tax benefit from giving it. (One of the things that makes social scientists skeptical of the benchmark survey Brooks used, in fact, is that it somehow concluded that liberals are richer than conservatives.)
The degree of religious contribution is important, because a 2007 study by Indiana University found that
only 10% to 25% of church donations end up being spent on social welfare purposes, of which assistance to the poor is only a subset. In other words, if you think of "giving" as "giving to the poor," a lot of the money donated by conservatives may be missing the target.