Jamil Zaki opens The War for Kindness by discussing the most important lesson he ever learned: “that two people’s experiences could differ so drastically, yet both be true and deep” (3). He explains how his parents’ divorce, which taught him to choose empathy, sparked his interest in empathy research. Divorce drove his mother and father apart; to maintain a close relationship with his parents, Zaki intentionally chose to try and understand their emotions.

To Zaki, empathy’s most critical function “is to inspire kindness: our tendency to help each other, even at a cost to ourselves” (4). Kindness puzzled evolutionary biologist Charles Darwin, who argued that “organisms should protect themselves above all costs” (4) to ensure the survival of their genes. Kindness, which could negatively impact an organism’s safety and survival rate, contradicts this idea. However, humans and other species both exhibit empathy and kindness toward close kin and friends. For example, when scientists electrically shock a rat, its cagemate will show anxiety and even give food to the hurt rat to alleviate its stress.

Empathy in humans, however, “took an evolutionary quantum leap” (5). The Homo sapiens species physically changed over millennia to make cooperation and connection easier.