The second study took place in the lab. Here, as each participant was working on onerous word problems, he (or she) witnessed the person sitting next to him, who was actually an actor playing the part of a second participant in the study, appear to be feeling too ill to complete work he had been assigned. We watched to see if participants would express compassion for this unwell person and offer to relieve his burden by taking on some of his workload. Doing so would constitute a purely compassionate act, as it meant spending more time in the lab toiling on unpleasant tasks in order to relieve the discomfort of another.

In both studies, the results were the same. Those who had faced increasingly severe adversities in life — loss of a loved one at an early age, threats of violence or the consequences of a natural disaster — were more likely to empathize with others in distress, and, as a result, feel more compassion for them. And of utmost importance, the more compassion they felt, the more money they donated (in the first study) or the more time they devoted to helping the other complete his work (in the second).

Now, if experiencing any type of hardship can make a person more compassionate, you might assume that the pinnacle of compassion would be reached when someone has experienced the exact trial or misfortune that another person is facing. Interestingly, this turns out to be dead wrong.

In an article recently published in the Journal of Personality and Social Psychology, the Kellogg School of Management professor Loran Nordgren and colleagues found that the human mind has a bit of a perverse glitch when it comes to remembering its own past hardships: It regularly makes them appear to be less distressing than they actually were.

As a result of this glitch, reflecting on your own past experience with a specific misfortune will very likely cause you to underappreciate just how trying that exact challenge can be for someone else (or was, in fact, for you at the time). You overcame it, you think; so should he. The result? You lack compassion.

To demonstrate the point, Professor Nordgren and colleagues collected information about their research participants’ past struggles with unemployment or bullying. In separate experiments, they next exposed them to people who were expressing dejection and showing difficulty in enduring one or the other hardship. Those who had overcome more severe bullying felt less — not more — compassion for current bullying victims. Likewise, those who had faced greater difficulty with unemployment had less sympathy for the currently jobless. When the adversities didn’t match, no such empathy gap emerged.

Our findings, taken together with those of Professor Nordgren and colleagues, bring some order to adversity’s seemingly contradictory effects. Living through hardship doesn’t either warm hearts or harden them; it does both. Having known suffering in life usually heightens the compassion we feel for others, except when the suffering involves specific painful events that we know all too well. Here, familiarity really does breed contempt.