By Tom Jacobs, Miller McCune

Measuring a person’s ecological footprint or carbon footprint is a popular tool among environmentalists. Many see it as a way to educate people about the damage they inflict on the environment on an everyday basis - information that may prompt them to change their behavior.

But newly published research suggests that for many people - perhaps most - the receipt of such data may produce the opposite result.

In an experiment described in the journal Social Influence, “Only people who had invested their self-esteem in environmentalism - a strong form of commitment - reacted to negative environmental-footprint feedback by engaging in a pro-environment behavior,” writes Santa Clara University psychologist Amara Brook. “Others were less likely to engage in a pro-environmental behavior after negative feedback.”

Given that “for most people in developed countries, environmental-footprint feedback is very negative,” Brook’s study calls into question the wisdom of providing such information.

Two hundred and twelve students (median age 19) participated in the experiment, which was conducted over a two-week period. First, they answered a set of questions measuring their self-esteem level and the degree to which their self-worth was contingent upon a commitment to preserving the environment.

The following week, they completed a version of the standard environmental-footprint questionnaire, which was slightly adapted to apply to student life. (It covers such issues as the number of miles you drive per year and the amount of locally-grown food you consume.)

The students then received their “score.” In fact, they were randomly chosen to receive either a high number or a low one.

Those receiving negative feedback were informed that, “In comparison to previous studies we have done with University of Michigan students, your footprint measures 140.23 percent of the footprint of the average University of Michigan student.” Those receiving positive feedback were told their footprint was only 55 percent of the average Michigan undergrad.

Finally, after reading a newspaper article about the environmental impact of various behaviors, “participants were given the opportunity to write a letter to the state governor on any public policy issue of their choice.” Brook wanted to see how many of them would address that topic.

Just under 44 percent of them did so - not a surprising figure, given the fact the issue was on their minds. Those for whom environmentalism and self-esteem were closely linked were more likely to choose the topic - and if they received negative feedback on their environmental-footprint report, they were the most likely to do so.

But it was a different story for the others. Among the noncommitted, those told they had a heavy environmental footprint were less likely to write about that subject. Perhaps they were eager to shove uncomfortable feelings of guilt or complicity out of their minds by focusing on another issue.

“These results suggest that environmental-footprint feedback only promotes sustainable behavior for people who are already committed to environmentalism and may discourage sustainable behavior among people who are not already committed to environmentalism,” Brook concludes.

Granted, this is one small study, and one can question whether the subject of one’s letter to the governor is a precise marker of environmental activism. (You could be pro-environment but still feel so strongly about another issue that you choose to focus on it in your plea to the state capital.)

But the findings track with those of an unpublished 2009 paper that found information regarding one’s environmental footprint led to “reduced feelings of self-efficacy,” which in turn “predicted lower intentions to engage in behaviors that reduce global warming.”

“Some psychological theories suggest that instead of changing their environmentally damaging behavior to match their environmental goals, people may react to negative feedback by changing their environmental views to match their behavior,” she notes. Her study suggests this thesis has merit.

So the environmental-footprint concept may have to be rethought, or at least placed in a context where it doesn’t lead to denial or despair. Brook suggests “giving specific, feasible recommendations” about how to live in a more environment-minded manner might produce more positive results.

That question awaits further research. What we know at this point is that encouraging environmentally friendly behavior remains a tricky, problematic endeavor. It seems admonishing someone for their large footprint can produce a big backlash.