Though lying can be an awfully convenient parenting crutch—Sorry, sweetheart, but the police might arrest you if I let you have more candy so we better not—it’s generally best to keep it to a minimum, both to develop trust between yourself and your child and to lead by example. Except in December. Because guess what? Not only is the Santa myth harmless, but it might actually be good for kids’ cognitive development. Fantastical stories foster a type of imaginative play that sparks creativity, social understanding and even—strange as it may sound—scientific reasoning.