We’ve heard all the complaints: We green-minded people are annoying. We’re self-righteous. We nag. We judge. And we don’t always practice what we preach.

But — not to sound like a broken record — there are some serious, civilization-threatening problems that we’re trying to tackle here. So what’s the best way to get other people on board with acting sustainably? Via Pacific Standard, here is a research-backed tip: Act nicely, and don’t make people feel like hypocrites.

In this study, researchers hung out in a supermarket and approached shoppers in one of three ways: letting them be; asking them to sign a poster that said “Stop using plastic bags. If I can do it, so can you”; or asking them to sign the poster and then “remember past transgressions” — i.e. not-so-green choices. The researchers called this last bit the “hypocrisy condition.”

Pacific Standard writes:

Later, at the checkout line, researchers compared the actions of all signers to those of a third group who had not been asked to do anything. Relative to the control group, the people who had simply signed the poster, with no follow-up question, were more likely to buy a reusable bag than take a free plastic one. The signers who were asked the question, however, used plastic bags at the same rate as the control group.

In short: Ask someone to do a helpful thing, and they’ll do it. Ask someone to do a helpful thing, and then make them feel bad about all the times they didn’t do it, and they’ll start thinking “I’m a good person. I do what I want! Like you’re so great, anyway. What do you know?” and do the exact opposite.