Tantrums may not be as common as you think! Researchers have developed a guide that helps parents and doctors determine when a tantrum is just part of toddlerhood, or if it's a sign of a behavioral problem. They surveyed the parents of more than 1500 preschoolers and found most tantrums happen when a child is tired or frustrated, or during mealtime and bedtime. They also found less than 10% of children have a daily tantrum. Children who have tantrums "out of the blue" or are so upset they become exhausted may need to be evaluated.