Harvard psychologist Daniel Gilbert, PhD, had the room in stitches as he bounded around the opening session stage, expounding on the secrets of happiness. And they're not what you think they are.

In a wide-ranging talk entitled "Happiness: What Your Mother Didn't Tell You," Gilbert said his mother told him the secrets to happiness were to get married, make money and have kids. "Was my mom right about any of this, or all of it?" he asked.

Marriage seems to be associated with happiness he said, showing statistics from research indicating that married people report being happier than unmarried people. However, after about 10 years of marriage, people report their happiness declines. "It's not marriage that makes you happy," he said, "it's a happy marriage that makes you happy."

Money does indeed buy happiness, he said, showing a slide indicating that people in more prosperous countries -- including the United States -- report being happier. "At some point, happiness keeps increasing [with income] but by smaller and smaller amounts," he said. When income reaches between $40,000 and $70,000 a year, "you've bought almost all the happiness you can get."

The reason some people with lots of money aren't happy isn't a problem of money per se, he said. "If money doesn't make you happy, you're not spending it right." And spending it right often means spending it on other people, he said.

As for kids, he said, "I have never seen a study that shows a positive correlation between children and happiness." Oh, wait, he added, there was one -- but the researcher withdrew it when it turned out to be flawed. While acknowledging that "your hearts tell you that your children are great sources of joy," the data say otherwise. Raising kids puts a great strain on happiness -- but one of the reasons people think children make them happy are those moments when, after a tough day with a 3-year-old, your child looks up with you, chocolate smeared all over his face, "and says, "Daddy, I wuv you,'" he said.

Gilbert warned against misinterpreting the data, though. "I never said you shouldn't have children," he said. And "I didn't say it was the kids' fault" that you're not happier. "Maybe you're not raising them right."

In conclusion, he said, "A, your mother does not know everything and B, you should call her anyway."