Testosterone certainly does not excuse the sometimes lethal behavior of physically aggressive males, but it certainly helps explain it. Animal research has indicated strong correlations exist between higher testosterone levels and more aggression. This relationship also holds true in research using human participants, although the correlations are generally weaker and it is unclear if testosterone causes aggressive behavior—some have speculated that perhaps aggressive acts trigger the release of more testosterone.
Nor can researchers ignore the effects culture might play in shaping the aggressive behavior of men. Albert Bandura’s social learning theory holds that behavior is learned from observing how others act. In short, men—and women—learn to be aggressive from watching others’ aggression; yet many men are aggressive while (thankfully) relatively few are homicidal maniacs.
Although psychological science is beginning to understand what makes people act aggressively, there is much still to learn about what might contribute to the blatant lack of empathy demonstrated by school shooters, terrorists, and others who show utter disregard for the lives of their victims and the victims’ survivors. The absence of empathy is another obvious commonality among all of the recent massacres, and it should be the goal of psychologists to better understand how to reverse this frightening trend.
Though tragedy is often born when high levels of aggression meet low levels of empathy, the compassionate response that follows is good news for humankind: as a culture, we are outraged and sickened by these despicable acts. We see acts of love and kindness in the face of adversity, we see survivors mourn their dead, and we see the nation rally together once again, if only fleetingly. We wouldn’t have it any other way. “We are all born for love,” wrote British Prime Minister Benjamin Disraeli, “It is the principle of existence, and its only end.”
