Most of us behave fairly consistently, for better or worse. You know this about yourself, and about your friends, family, and even acquaintances, once you’ve had some experience with them.

A memorable example occurred at the funeral for the husband of a very close friend. Nigel died of cancer at the age of 57, and, as a man much beloved by his family, friends, and the community, the event was overflowing with mourners. Beforehand, I had made plans to travel to the gravesite with his widow, Glenda, but after it was hard to find her in the crush of people giving their condolences. Another friend of hers, Paul, suggested that I drive out to the cemetery with him and his wife, and I said I couldn’t do that because Glenda would be worried about what happened to me. Paul replied that worrying about me was the last thing on Glenda’s mind, but I knew her better I guess, because when I worked my way through to her she had indeed been concerned about finding me.

This is an example of the trait theory of personality. Since reliability and awareness of others are among Glenda’s most prominent features, I reasoned that even under extreme stress she would exhibit these character traits.

Studies have shown, however, that in certain circumstances many people respond more to the situation and don’t necessarily respond the way they usually do. Divinity students who rated high on a measure of concern for others were shown to stop more frequently to help a troubled stranger compared to a control group. However, the same group of students, when they were hurrying to meet the dean for an appointment, passed the stranger without helping more often. And the greater their hurry, the less likely they were to stop.

In this “Good Samaritan Study,” 10% of the students still stopped to help the stranger even when they were an “extreme hurry” situation. This implies that for some people, some of their internal traits will endure regardless of external circumstances.

The question of conditions that cause people to abandon their internal values was of great concern after the Holocaust. Philosophers, historians, and psychologists were anxious to discover why so many people were willing to cooperate with, and sometimes aid the Nazis. Stanley Milgram, a professor at Yale, set up a now famous experiment in 1961 that had troubling results.

Milgram hypothesized that since many war criminals reported they had been “following orders,” he would test the trait of obedience to authority. Briefly, he set a condition in which volunteers who were subjects were told to administer electric shocks to strangers who failed answers on a word test. A man in a white coat instructed the volunteers to give higher levels of shocks after each successive failure. The “strangers,” unseen but able to be heard, were actually colluding with the “scientist,” and were not actually feelings the shocks. But the volunteers did not know that, and the strangers could be heard screaming in more and more pain as each incremental rise in shock was delivered. People chosen randomly from the New Haven community, the volunteers, showed signs of distress and some complained, but 65% continued to obey until the very highest level of shock (labeled “extreme danger XXX”) when the “scientist” said, “keep going.” Beforehand, Milgram and his associates had hypothesized that only 3 of 100 would proceed to that level.

Though the experiment led to questions about the ethics of duping subjects, the conclusions were replicated in 1999. Milgram explained in his book on the subject, called Obedience to Authority (1974):

“Ordinary people, simply doing their jobs, and without any particular hostility on their part, can become agents in a terrible destructive process. Moreover, even when the destructive effects of their work become patently clear, and they are asked to carry out actions incompatible with fundamental standards of morality, relatively few people have the resources needed to resist authority.”

So what can we conclude from this about the nature of personality? While we are mostly consistent, circumstances do have a large effect on our behavior, and how we understand a situation can make all the difference. The Yale volunteers were heavily influenced by the status of the University, the institutional setting, and the authority the lab coat conferred to the “scientist.” Debriefed after, the subjects said ordinarily they would not deliberately hurt a stranger, and the authority of the Yale “doctors” overshadowed their sense of personal responsibility.

There is another side to this question, though. If the lens through which we view something affects our behavior, it can also affect our feelings, and by changing that lens, we can change. This is the essence of cognitive psychology: if you can reframe the way you view something, you can change the way you feel and react.