The article on happiness as requested...

The happiest people

So what makes us happy? Somewhat surprisingly, the older you get the happier you are -- until you reach very old age. According to a US study, the happiest age group is men 65 and older. The least happy group? Men aged from 18 to 29. The survey, conducted by the Pew Research Center, also found:

- Married people are happier than singles.

- University graduates are happier than those without a university degree.

- People who are religious are happier than those who aren't.

- People who live in sun-belt areas are happier than those who don't

And what role does money play in determining happiness? Daniel Gilbert, author of the book "Stumbling on Happiness" told CNN that money helps to buy happiness -- but only to a degree.

"Our culture implores us to buy bigger, newer, better things, but research shows 'stuff' does not buy happiness. By and large, money buys happiness only for those who lack the basic needs. Once you pass an income of $50,000, more money doesn't buy much more happiness," Gilbert said.

What about people who are disabled? They are about as happy on a day-to-day basis as the general population, according to Gilbert.

And while many parents may vehemently disagree, Gilbert said that having children can have a negative effect on happiness. "When you follow people throughout their days, as they're going about their normal activities, people are about as happy interacting with their children, on average, as when they're doing housework. They're much less happy than when they're exercising, sleeping, grocery shopping, hanging out with friends," Gilbert told CNN. "Now, that doesn't mean they don't occasionally create these transcendent moments of joy that we remember as filling our days with happiness."

The failure to obtain happiness could also be the result of a faulty imagination or unrealistic expectations. Our imaginations fail us, Gilbert said, because when we envision different futures we see either perpetual gloom or happily ever-after scenarios. In fact, neither unhappiness nor joy last as long as we expect.

To better predict what will bring you happiness, Gilbert says to remember that people are not unique in what makes them happy.

"If I wanted to know what a certain future would feel like to me I would find someone who is already living that future," he said. "If I wonder what it's like to become a lawyer or marry a busy executive or eat at a particular restaurant my best bet is to find people who have actually done these things and see how happy they are."

Top 10 happiest countries

Here are the top 10 happiest countries, according to the CNN report:

1. Denmark

2. Switzerland

3. Mexico

4. Canada

5. United States

6. United Kingdom

7. Venezuela

8. Nigeria

9. China

10. Japan