SAFEGUARDING the environment ranks high on political and social surveys. Yet a yawning gap exists between good intentions and reality. Although Americans express strong support for reducing air and ground pollution, few give up their cars or recycle their AA batteries instead of throwing them in the trash.

Why are people’s words and actions so contradictory? Economists who study such behavior say the only variables that really matter to most individuals are time and money: How much would a gallon of gasoline have to cost before the masses switch to mass transit? How frequently would buses have to run to attract crowds of riders? Fortunately, experts in the young discipline of environmental psychology point out that other influences can strongly affect our choices. Understanding these dynamics, and how to exploit them, may prod citizens to embrace greener ways.

Changing Attitudes

One feature to plumb is personality. P. Wesley Schultz, professor of psychology at California State University, San Marcos, is studying one trait that, surprisingly, has been largely ignored: the extent to which people feel they are part of the natural world. Schultz measures attachment to nature with a variation of the widely used Implicit Association Test. The computerized exercise determines how strongly a person associates his or her self-image with a particular concept, such as “trees” or “factory.”

In a 2005 study Schultz found that individuals who demonstrated either a close or distant connection with nature could be moved by a long visit to a certain place. Subjects who spent a day at the zoo or on a hiking trail felt, at the end, somewhat more closely connected to nature than when they spent a day in a library or at a health club. Schultz concluded that attachment to nature is not a personality characteristic that is carved in stone. His results suggest that it would be much easier to convince people to protect nature if they had direct experience with it—which is the force behind the rise of ecotourism.

Other characteristics, such as age, also influence how ecologically minded a person may behave. Although young people express concern for the environment, they are somewhat less likely to behave in an environmentally sustainable way than are older people. Political orientation holds sway as well: conservatives care significantly less about protecting the earth than do people who describe themselves as liberals.

More important, according to some environmental psychologists, are basic attitudes. According to one accepted model called the theory of planned behavior, created by psychology professor Icek Ajzen of the University of Massachusetts Amherst, three factors determine whether we choose to carry out any particular action: attitude toward the behavior (Are the probable consequences of my deed compatible with my convictions?); social norms (Do others, whose opinions matter to me, expect me to behave like this?); and perceived behavioral control (Can I see anything that might help or hinder my carrying out this action?).

Only when all three questions can be answered positively do we conclude that we will actually carry out a proposed action. Christoph Weber, now at the University of Duisberg-Essen in Germany, tested this assessment on 240 people who planned to relocate to Stuttgart. Before they moved, half the group received a packet about the Stuttgart transit system that explained which bus stop would be nearest to their new address and provided a schedule for that line. Some envelopes included a one-day bus pass as an incentive. Weber surveyed the participants several weeks after they moved and found that those who had received the mailing did leave their cars at home more often. He concluded that because they knew more about departure times and connections, they were far more convinced that they could make sensible choices about how to get to work. The most avid transit users also indicated that the opinions of their friends and families had pushed them in the direction of taking buses.

Changing Habits

The theory of planned behavior assumes that we carefully consider pros and cons, which may be true in novel situations such as moving to a new city. But the theory neglects an important point: in everyday life we tend to be creatures of habit. We may have to overcome many habitual, or automated, acts to exhibit greener behavior. The decision to leave the lights on as we walk out of a room or to check the recycling symbol on a plastic container instead of just throwing it away may rarely involve conscious consideration.

Some environmental researchers also overlook very real constraints that can limit a person’s choices. Florian G. Kaiser, who teaches social and environmental psychology at the Eindhoven University of Technology in the Netherlands, notes that positive attitudes toward nature are of little value without opportunities to take action. For example, whether or not the only supermarket near an individual’s home carries eggs from free-range chickens will most likely be the only factor determining whether that person buys free-range eggs.

Kaiser examined the power of objective constraints by analyzing how students with different academic majors in Andalusia (in southern Spain) and in Switzerland engaged with green issues. He found that Spanish environmental science students behaved almost exactly like their local friends in business school but completely differently from Swiss environmental science students, even though the Swiss students shared a similar awareness of environmental issues.

Why the irony? Kaiser points out that students in balmy Andalusia were less concerned with the use of heating fuel than the Swiss were, but that is simply because the climate is warmer. And the Swiss donated more to green organizations and bought more organic products simply because they had more disposable income.

Such findings cast doubt on the sway of ephemeral factors such as a country’s pride in environmental consciousness and raise the profile of pedestrian issues such as knowledge about bus schedules and money for organic fruit. As enthusiasts try to encourage others to act greener, they must consider basic practical factors and not just attractive philosophies.