Does belief in Santa Claus hamper or hinder critical thinking?

It’s that time of year again when families deck the halls, trim the tree, and pick sides in the perennial battle between believers and non-believers … in Santa Claus that is.

Among believer families, parents prime their kids for Christmas morning with stories of toymaking elves, flying reindeer, and an omniscient old man in a red suit, while non-believers urge their children not to burst their friends’ Santa-bubble quite yet.

In some cases, the fault line runs right through families.

Erin McLaughlin of Watertown, Mass. wants her 7-year-old daughter to believe in Santa Claus “for as long as possible,” while her husband Eric “thinks we are doing her a disservice by perpetuating this untruth.”

Eric is not the only parent who is uncomfortable with what he thinks amounts to lying to children.

David Kyle Johnson, a philosophy professor at King’s College, a Catholic college in Wilkes-Barre, Penn., has written numerous blog posts, articles, and book chapters denouncing the “Santa lie.”

“Lying is wrong,” Prof. Johnson says. “There are certain reasons when lying becomes acceptable, but being amused by your kids’ naïveté is not one of the justifiable reasons to lie.”

For that very reason, some parents opt to skip the Santa myth entirely or to present it as a fictional story. Others avoid the Santa tale in an effort to maintain the religious significance of the holiday.

However, the majority of American parents apparently do encourage their children to believe in Santa. In 2011, 57 percent of families reported that Santa played an important role in their holiday tradition, according to an AP-GfK poll, 29 percent said that Santa played a “very important” role. (It is not clear whether that amounts to literal belief in Santa Claus or celebration of the fictional character.)

For many parents, Santa Claus is a joyful part of childhood that enhances the fun of Christmas, encourages imagination, and later, as kids start to get wise to the myth, promotes critical thinking, says Karl Rosengren. The developmental psychologist and fellow researchers at Northwestern University, in Evanston, Ill., has conducted a series of studies and surveys of parents’ attitudes towards belief in fantasy.

“One of the things that struck us is that most parents hadn’t ever thought too deeply about why they encourage these beliefs, but they continue to do it because that’s how they were raised,” Prof. Rosengren says. “Parents talk about encouraging fantasy helping with cognitive development and creativity, and, as a developmental psychologist, I really can’t see anything wrong with it.”

“I think I like the idea of the magic in childhood,” one parent responded to Rosengren’s survey. “We’ll let it go as long as she’s willing to believe.”

Johnson sees that moment when kids’ belief begins to fade as a critical point in the formation of children’s ability to think critically and maintain trust.

A real problem arises when parents “encourage kids to keep believing even after they express doubts," he says.

“In general we have a critical thinking problem in this country,” he says. “A good portion of my students believes that Chris Angel [an illusionist] really can walk on water. Many believe in ghosts. I’m not saying that the Santa myth is to blame, but perpetuating the myth and encouraging kids to ignore their intuition about what’s real and what’s not is a real problem.”

On the other hand, parenting experts and psychologists suggest that helping to guide children through the process of realizing that Santa is not real can lay the foundation for critical thinking skills.

The Santa myth “is a way to have kids engage in a harmless cultural myth and to think their way out of it,” says Dale McGowan, a former critical thinking professor and author of “Parenting Without Belief” and “Raising Free Thinkers.”

When Mr. McGowan’s son was young, he was careful to couch the Santa tale with phrases such as, “some people say” and encourage his son to share what he thought.

“When he looked at me and asked, ‘Is Santa real?’ I asked, ‘What do you think?’ and he replied, ‘I think it’s the moms and dads!’ He was so excited that he had this idea. I said, ‘Good for you, you figured it out.' ”

While some adults worry that children will be traumatized when they learn that Santa – and all the various props and lore that support the myth – is nothing but a ruse, McGowan maintains that such distress really comes from parents attempting to sustain the myth beyond its natural course.

For most children, the pivotal age seems to be around 7- or 8-years-old, psychologists at the University of Montreal and the University of Ottawa have found.

“Children start to ask questions at around 5- or 6-years-old, but they will invent [or accept] excuses that let them continue to believe,” says Carole Sénéchal, a psychologist at the University of Ottawa who has studied belief in Santa Claus. “But when they reach 7- or 8-years-old, they start to notice that Santa is at the mall at the same time as in a parade and recognize that there cannot be 2000 Santa’s all over the world at the same time.”

At that point, parents have a responsibility to guide their children through the realization process and should not attempt to prolong belief any longer, Prof. Sénéchal says.

Until then, “For some kids the only good thing they have is Christmas,” she says. No matter what life is like at home, “you have a moment during the year when somebody is nice and is a good example.”