The emotional responses that guide much of human behavior have a tremendous impact on public policy and international affairs, prompting government officials to make decisions in response to a crisis–such as the Sept. 11 terrorist attacks–with little regard to the long-term consequences, according to a study by scholars at Carnegie Mellon University and the University of Pittsburgh School of Law. The paper (PDF), which appears in the Chicago-Kent Law Review, was written by Jules Lobel, a Pitt professor of law, and George Loewenstein, professor of economics and psychology at Carnegie Mellon.

Intense emotions can undermine a person’s capacity for rational decision-making, even when the individual is aware of the need to make careful decisions. With regard to public policy, when people are angry, afraid or in other elevated emotional states, they tend to favor symbolic, viscerally satisfying solutions to problems over more substantive, complex, but ultimately more effective policies. Over the past 40 years, this has led the United States into two costly and controversial wars, in Vietnam and Iraq, when members of Congress gave the president broad powers in response to a perceived crisis that did not leave sufficient time for deliberation.

“War is the quintessential issue where immediate emotions and passions hold sway, often at the expense of an evaluation of long-term consequences,” Lobel said.

The authors draw on recent research that demonstrates that human decision-making is governed by two neural systems–the deliberative and the affective, or emotional. The latter, which the authors dub emote control, is much older, and served an adaptive role in early humans by helping them meet basic needs and identify and respond quickly to danger. As humans evolved, however, they developed the ability to consider the long-term consequences of their behavior and to weigh the costs and benefits of their choices. The deliberative system appears to be located in the brain’s prefrontal cortex, which grew on top of but did not replace older brain systems.

“Human behavior is not under the sole control of emotion or deliberation but results from the interaction of these two processes,” Loewenstein said.

Emote control is fast, but can respond only to a limited amount of situations, while deliberation is far more flexible but relatively slow and laborious. Emote control is the default decision-making system. Deliberation kicks in when a person encounters a situation that is new or when the correct response is not evident. Emote control is highly attuned to vivid imagery, immediacy and novelty, meaning that the emotional system is more likely to respond to events that are associated with striking visual images, that occurred in the recent past, and that people are unfamiliar with and have not had time to adapt to. Emotion also is sensitive to the categories into which humans automatically place the people and things they encounter–from the perspective of law and social policy, the all-important distinction between “us” and “them.” And emote control can activate deliberation, according to Loewenstein and Lobel.

“Moderate levels of fear, anger or any almost any form of negative emotion warn the deliberative system that something is wrong and that its capabilities are required. Perversely, as emotion intensifies, however, it tends to assume control over behavior even as it triggers the deliberative system, so one may realize what the best course of action is, but find one’s self doing the opposite,” Loewenstein said.

This means that the situations that most require a careful, well-reasoned response are those in which our emotions are most likely to sabotage our long-term interests. America’s founding fathers understood that passion could trump principle and therefore vested Congress, a deliberative body in which power is dispersed among dozens of members, with the power to make war, rather than with the president. But that constitutional safeguard began to erode in the 20th century because of the sense of perpetual crisis that emerged during the Cold War and escalated as a result of the Sept. 11, 2001 terrorist attacks. The calamitous nature of those attacks gave Americans a distorted sense of the true risk of being killed in a terrorist attack–which is quite low–and policy makers responded with an expansion of federal law enforcement powers, cumbersome security measures and a new war that may ultimately be self-defeating. If, for example, new airport screening procedures prompt more people to drive rather than fly, traffic fatalities will increase, and because driving is far more dangerous than flying, on balance more people will die, even assuming a steady rate of terrorist attacks.

“The problem of vivid, emotional miscalculation of risk is particularly acute in the context of antiterrorism, since fear is a particularly strong emotion, impervious to reason,” Lobel said.

Lobel and Loewenstein do not, of course, suggest that emotions are always bad and point out that properly harnessed passions helped defeat Nazism, put a man on the moon and reduced air pollution. Yet political leaders can exploit emotions for their own ends, so as a society, we must recognize the havoc that emotions can play on public policy, and government should adopt legal safeguards that slow the pace of decision-making so that lawmakers have time to weigh the consequences of their choices.

“Human psychology hasn’t changed much, but politicians and marketers have become ever more sophisticated when it comes to manipulating people by manipulating their emotions. One of the functions of law should be to keep deliberative control in the picture, especially at times of high emotion when it is needed the most,” Loewenstein said.