For a world that’s messed up, we sure have a lot of goodness being shoved in our faces.

If we’re not hearing about Angelina Jolie’s impending sainthood (a profile in the July issue of Esquire magazine unblinkingly calls her “the best woman in the world”), we’re busy trying to convert our cars to run on nothing but lavender oil and beer. Folks who as recently as the mid-’90s were littering on their grannies’ front yards and mocking mentors of any kind are now buying back carbon emissions, volunteering in droves (61.2 million last year, according to the Bureau of Labor Statistics) and somehow resisting the urge to physically attack those people who stand outside Trader Joe’s asking, “Do you have a moment for the environment?”

Why such munificence? Being good feels good, of course (unless it involves not eating cheese), but apparently it also makes us live longer.

At least that’s the theory put forth in the new book “Why Good Things Happen to Good People: The Exciting New Research That Proves the Link Between Doing Good and Living a Longer, Healthier, Happier Life.” Citing his own research as well as numerous other studies, Stephen Post, a professor of bioethics at Case Western Reserve University’s School of Medicine, and co-writer Jill Neimark suggest that there’s a direct connection between altruism and physical health.

A 2005 study from Stanford University, for example, found a link between volunteerism and “later mortality” among the elderly. A large survey of teenagers in Vermont found that those who volunteered were less likely to engage in risky behaviors. And in a British study the authors call “truly remarkable,” neighborhoods that had high rates of volunteerism were found to have lower rates of crime, better schools and “happier, healthier residents.”

OK, so one man’s “truly remarkable” is another’s “no duh.” Don’t communities that have higher rates of volunteerism also tend to have higher tax bases with which to fund police departments and schools? And don’t they also have more golf courses and gelato shops to keep residents happy and healthy?

Still, as frustratingly facile as “Why Good Things Happen to Good People” is (it contains such sentences as “Every time Christina Noble helps an orphan child in Vietnam or Mongolia, she helps the little girl inside herself.”), it’s also more honest about the psychology of altruism than the authors seem to realize. That’s because in trying to convince us that doing good makes us live longer, they present “goodness” as a concept that has more to do with individual ego than anything else. Like a child who receives gushing praise for behavior that should be a matter of course, we’re being told that ordinary compassion is, in fact, extraordinary. Therefore, hearty self-congratulations are in order.

It’s an ingenious marketing strategy. By viewing magnanimity as a personal goal (like getting tighter abs) rather than simple civility (like not spitting at people), we turn goodness into a form of self-help. We give to others not because it’s the right thing to do but because, as with yoga or meditation or high colonics, it helps us feel better.

There’s nothing necessarily wrong with people doing good deeds for less than selfless reasons. Before there was Prozac, there was the good feeling that came from serving meals to the homeless. And before there was Internet dating, there was Habitat for Humanity. But today, goodness isn’t just cool, it’s the new snowboarding.

There is, for example, the eminently hip magazine “Good,” which covers issues related to progressive culture and politics and funnels subscription fees into charitable groups of the readers’ choosing (its associate publisher, incidentally, is that Dale Earnhardt Jr. of Prius drivers also known as Al Gore III). Web-based organizations including “Do Something” and “Action Without Borders” connect young people with various volunteer opportunities and attract tens of thousands of hits a day – no surprise, because a study last fall suggested that 81 percent of 13- to 25-year-olds had performed volunteer work in the previous year.

This is all, you know, good. Even if teenagers go through the motions to impress college admissions officers, and even if baby boomers use compassion as an anti-aging cream, some folks seem genuinely to have a stake in improving the world, or at least in keeping the apocalypse at bay until they have cataracts and can’t see what’s happening.

So why can’t I get past the smugness and appreciate the sincerity? Maybe because too many people seem to see goodness as the kind of tree that doesn’t exist unless someone is around to hear it fall. And that’s no way to save a forest.