It’s true that religion is the essential reason conservatives give more, and religious liberals are as generous as religious conservatives. Among the stingiest of the stingy are secular conservatives.

According to Google’s figures, if donations to all religious organizations are excluded, liberals give slightly more to charity than conservatives do. But Mr. Brooks says that if measuring by the percentage of income given, conservatives are more generous than liberals even to secular causes…

Conservatives also appear to be more generous than liberals in nonfinancial ways. People in red states are considerably more likely to volunteer for good causes, and conservatives give blood more often. If liberals and moderates gave blood as often as conservatives, Mr. Brooks said, the American blood supply would increase by 45 percent.