One cartoon used shows a man standing in a telephone booth with the caption, "Here is the answering machine of the self-help association for Alzheimer patients. If you still remember your topic, please speak after the tone."
Researchers found subjects fit into one of three groups. Those who appreciated or processed black humor best were in a group that had the highest verbal and non-verbal IQ, as well as higher education levels. That group also tended to have "no mood disturbance and low aggressiveness." They didn't find any correlation between age or gender.
Part of the explanation for what they found was that enjoying black humor is a "complex information-processing task." They also concluded that "emotional instability and higher aggressiveness apparently lead to decreased levels of pleasure when dealing with black humour. "
So next time someone decides to tell you you're terrible because of a joke you enjoy, just smile and know it probably means you're smarter than they are.