Being a mom makes you happy (Courtesy of Parenting.com)

In fact, around the world, children top the list of the most enjoyable things in life.

But psychologists who study happiness  -- a new field in the past decade  -- often report a different picture. Being the mom of a young child (especially one under 3) is rich and rewarding, but also a real strain on your mood. "Moment to moment, you may be exhausted, frustrated, sometimes angry," says Peter Ubel, M.D., a professor of medicine and psychology at the University of Michigan. "You may be squabbling with your spouse more. You have more negative emotions."

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The time you spend taking care of your child may not even be the high point of your day. On their list of pleasurable activities, moms rank it lower than eating, exercising, or watching TV, according to a University of Michigan study of 900 women. In fact, kid care rates only slightly higher than housework, working, or commuting!

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"This finding shocks people," says Daniel Gilbert, Ph.D., a psychology professor at Harvard University and author of Stumbling on Happiness. "They think psychologists are saying you don't love your children. Of course you love your children beyond measure! And kids do bring joy. They bring transcendent moments in which you feel so happy that it outweighs all the hard work you've done. It's just that children do not increase your average daily enjoyment."

The happiness paradox
One reason for the discrepancy between moms and experts: selective memory. When psychologists ask moms in a general way if they like spending time with their kids, the overwhelming majority say they do because they're thinking of fun activities like reading a book or playing in the park. When they're specifically asked to describe their actual daily routine, they remember the hours they spent struggling to get their child dressed or ready for bed.

Maybe, though, the cold calculus of psychological science is missing the intensity of joy that time spent with your child can bring. "There are little moments that are grand-slam home runs," says Gilbert.

Luckily, those moments can overcome your daily frustrations. "Happiness is more than just that smiley feeling," says Karen Reivich, Ph.D., a research associate in the Positive Psychology Center at the University of Pennsylvania. "It's also feeling a connection to something larger than yourself. When people are in service to something bigger, they describe their lives as filled with meaning. It's not the smiley face, but when it's all over, you realize you'd do it again."

And being needed is a rewarding experience as well. "You get back tenfold everything that you put into it," says Elizabeth Howard, mom of Reilly, 2, in Anaheim, California. "I don't think people should have a child just to make them happy, but it's opened up a whole part of my heart that I didn't even know was there."

The first step to being a happier mom, then, is to value what you do  -- to feel that it's important. The next step is to find ways to make it more enjoyable. Not only will you be doing the best thing for yourself, but you'll also become a more effective mom. Say you're with your 2-year-old and she wants her juice in the red cup, but the red cup is missing. "If I'm in a grumpy mood, I may just say, 'Drink it in the blue cup,'" says Reivich. "But if I'm feeling more positive, maybe I'll take some red construction paper and tape it around the blue cup. I've transformed something that might get ugly into something playful and fun."

The good news for all moms is this: You can learn to focus on the positive  -- and learn to make it a daily habit. Here's how:

Admit when you're stressed
Ironically, once you stop expecting motherhood to feel warm and fuzzy all the time, life as a mom gets easier. "It really helps to realize that it's okay to feel frustrated, angry, tired, or irritable sometimes," says Dr. Ubel. "You're not a bad parent. It's not even a bad parenting experience. It's just normal."