"A witch is defined as a person who signed the devil's book, thus giving the devil permission to use her shape to go around harming other people." The Salem Witch Trials were brought about when a group of young girls claimed to be possessed by the devil after they were seen dancing in the forest. The girls started displaying wild and peculiar behavior that a local doctor, William Griggs, diagnosed as bewitchment. The Salem Witch Trials had a negative impact on American history because it caused mass hysteria that spread throughout colonial Massachusetts, was fueled by residents suspicion of and resentment toward their neighbors, and the belief in the devil's practice of giving certain humans the power to harm others in return for their loyalty.