Adults use three tools to decide what to believe:

• The context in which you are introduced to new information will guide your judgment to accept it.
• The tendency to measure new information against existing knowledge.
• The ability to evaluate the expertise of other people.

Children use the same tools to decide what to believe. When children hear about something in a fantastical context, they are less likely to think it is real than if they heard about it in a scientific context or from a knowledgeable person.

Parents and others go to great lengths to overwhelm children with evidence about Santa.

• 84% of parents report taking their child to visit at least two Santa impersonators during Christmas season.
• The Elf on the Shelf is now a multi-million-dollar franchise.
• The United States Postal Service promotes "Letters from Santa" programs which provides personal replies to children's letters.

Some philosophers and bloggers claim that engaging in the Santa myth can lead to permanent distrust of parents. However, there is no evidence that it affects parental trust in any significant way.

As children's understanding becomes sophisticated, they can engage with the absurdities of Santa, such as how an overweight man can fit through a small chimney.