Why are people spiteful?

Celebrities locked in legal battles and parents in the middle of a nasty divorce are more prone to carry out some act of vindictiveness against the opposing party -- even if it means getting hurt themselves.

So what makes a person willing to pay the price of that self-inflicted pain?

The study, "The Psychology of Spite and the Measurement of Spitefulness," published February in the journal Psychological Assessment, explored that question.

Spite involves "hurting others with the risk of also hurting one's self," said David Marcus, a psychology professor at Washington State University, one of the co-authors the study.

Researchers define spitefulness as "an element of self-harm can be a powerful motive with potentially serious and often negative psychological, interpersonal, and societal consequences."

Spite carries a risk to both the aggressor and the receiver of the pain whereas with just aggression, the pain is almost always received by just the target.

Marcus said this concept can be seen in the "ultimatum games" used by economists, where a player is asked to divide an amount of money any way they see fit between two players -- no matter how uneven the amount might be.

If a second player does not take the offer, no players we receive the cash. Within the study's context, a player may reject the lower amount due to feelings of spite.

To investigate the impact of spite further, Marcus, along with researchers at Oakland University and the University of British Columbia, developed a "spitefulness scale" to measure the types of personality traits that emerge in certain scenarios when spite could be a factor.

They used those results to gauge how high or low the participant's level of spite ranked.

Researchers surveyed more than 1,200 people at two universities in a 17-question online assessment. They also collected data from participants through an Amazon survey.

Survey participants were asked how strongly they agreed or disagreed with scenarios like: "If my neighbor complained about the appearance of my front yard, I would be tempted to make it look worse just to annoy him or her," or "Part of me enjoys seeing the people I do not like fail even if their failure hurts me in some way."

Researchers found the personality traits that were associated with spitefulness included: "aggression, psychopathy, Machiavellian-ism, narcissism, and guilt-free shame," while the personality traits that were associated with opposite of spitefulness included: "self-esteem, guilt-proneness, agreeableness, and conscientiousness."

The survey discovered that men and younger people tended to be more spiteful than women. One of reasons may be due to the scenarios used elicited a less aggressive reaction from women, Marcus said.

The survey also discovered that older people are just not that spiteful.

"As we get older, we get less spiteful on average," Marcus said, adding that the reason, at least anecdotally, could be due to hindsight. "You get older and you learn from experience and you just may not have the energy for it."

Researchers hope that these results will be able to help them predict behavior in both a lab setting and develop real-life applications to situations that require investigating behavioral motivations in the future.