Thinking Caps are used to preserve the integrity of the tests during Midterms and Finals. They are made of a thick white cloth that falls into a point and goes around a prodigy's head. It is also made of an amalgam of metals that dull telepathic abilities. Sophie thinks that they look like smurf hats. The hats don't block Sophie's Telepathic abilities, which amazed Tiergan to the point that he instantly gave her a score of hundred on her telepathy midterms. Variants of this product have been created, as shown through the hat the ogre rebels used to block Grady's mesmerizing in Book 5.