Book excerpt: "Most parents of toddlers and preschoolers know a thing or two about tantrums--those epic meltdowns that seem to come out of nowhere. Even though tantrums can be part of "normal" toddler behavior, they are maddening, stressful, and exhausting. What can parents do to help everyone step back and calm down? With candor and wit, Rebecca Schrag Hershberg, psychologist and mom of two, explains the science behind why tantrums occur and what parents might unintentionally be doing to encourage them. She offers a customizable plan for nipping blowups in the bud while fostering healthy development and deeper parent-child connections. Imagine family life with equal measures of love and limits--and less drama"--