Parents who say their kids bring them untold happiness may be idealizing parenthood to feel better about the costs of parenthood and the fact that they could've been a whole lot richer if they had just stayed child-free.

A new study by two social psychologists at the University of Waterloo, suggests parents see family life through rose-coloured glasses in order to justify the huge amount of energy and money kids drain from them.

For their study, which appears in the journal Psychological Science, Profs. Richard Eibach and Steven Mock recruited 80 fathers and mothers of kids under 18. Half of the parents were given the cold, hard facts about the financial costs of parenting: U.S. government data estimates the cost of raising a single child to the age of 18 amounts to more than US$190,000.

The other parents got this information too, but they also read about the financial benefits of parenting -- the fact that adult children can provide financial and practical support to aging parents.

The parents were then given two psychological tests: One measured their feelings of discomfort and uneasiness during the experiment. The other looked at how much they idealized parenting, by asking such questions as "Do you agree that there is nothing more rewarding than raising a child?" and "Do adults without kids experience emptiness in their lives?"

The researchers expected the first group of parents would focus mostly on the costs of kids, while the others would see parenthood a "mixed blessing," financially.

As expected, the parents who were asked to think only about the financial costs felt much more discomfort than the parents given the mixed view. But if the scientists first measured whether the parents idealized family life and then measured their discomfort, the parents reported no feeling of distress.

In other words, the parents slipped into an idealized view of parenting despite their knowledge of the huge costs of parenting. It's what psychologists like to call rationalization in the face of "cognitive dissonance."

Eibach finds this dissonance fascinating, given that the belief that parenthood brings its own rewards is a bit of a myth. Research has shown that parents do not have more emotionally satisfying lives than non-parents.

"There have been scores of studies that compared the happiness and life satisfaction of parents to non-parents and they found no evidence that parents experience greater well-being; in fact, they've found just the reverse," Eibach said in an interview.

Parents tend to have more stress, more dissatisfaction with their work-life balance, and more marriage discord than non-parents. They also have a whole lot less money in their bank accounts.

Yet the myth persists that parents are happier than non-parents.

"As a social psychologist, I'm always interested in where these popular myths come from and persist," Eibach said.

He thinks the idea formed around the time when kids shifted from being economic contributors to becoming economic burdens. As the value of children diminished and their costs escalated, a belief took hold that parenthood brings its own intangible, emotional rewards.

It's a belief that Eibach believes his study demonstrates parents choose to cling to, to help them cope with the hard financial burden of raising kids.

Now, before you worry that Eibach hates children, or likes to sneer at parents, rest assured his study was not meant to indict parenthood.

"We're not attacking parenthood. We're helping to explain the strong commitment that parents make to raising their kids and the underlying psychology of that," he explained.

If parents really do idealize their parenthood even in the face of its hard financial realities, are parents lying to themselves? And if so, do they realize they're doing it?

"That's an interesting question," Eibach said, lamenting that his study didn't seek to answer that question.

But no, he doesn't believe that parents are delusional. They are simply rationalizing their decision -- something all humans do every day. Consumers, for example, make all sorts of seemingly illogical shopping choices, justifying the cost of a $5 coffee in a fancy coffee place when they know they can get coffee for $1.50 down the street, for example.

"There's nothing special about parents," Eibach said. "When people make sacrifices for pretty much any activity, they then seem to feel some need to convince themselves that they enjoy that activity more than they would have said if they hadn't made those sacrifices."

And when parents say that raising kids is rewarding, they're not wrong: parenting does bring plenty of joy.

"Parents are not making this up or completely fabricating this; they're probably just focusing more on the emotional rewards than the burdens. It's what we call a motivated deployment of attention," said Eibach.

In an interesting follow-up study, Eibach's team asked parents to compare the enjoyment of spending time with their kids, compared to other ways they could be spending their time, such as with their partner, or with friends.

Again, if the researchers pointed out the costs of having children, the parents tended to exaggerate how much they enjoyed spending time with their kids versus spending times in other ways.

And when they asked the parents how much leisure time they hoped to spend with their child on their next day off from work, they found that the parents who had the high costs of parenthood in mind were more likely to say they looked forward to spending more time with their kids.

In other words, being aware of parenthood's price tag made them idealize the time they spent with their kids, and led them to want to spend even more time with them.

"So that's one potential benefit of these myths: It might leave parents to spend more time with their kids, which is of course good for families and kids," Eibach said.

So keep wearing those rose-cloured glasses, and go forth and multiply.