Narcissistic people aren’t known for being generous. But emerging research suggests that narcissistic people may be willing to engage in charitable activities in certain situations, a finding that could have implications for nonprofits seeking to design more effective appeals.

While narcissism’s dark side is well-documented, with dozens of studies showing narcissists’ difficulty with close relationships and their tendencies to lash out aggressively when someone insults them, comparatively little is known about how and why...