Book excerpt: Now updated! The new edition of this best-selling guide uses science to tackle some of the most important decisions facing new parents—from sleep training and vaccinations to breastfeeding and baby food. Is cosleeping safe? How important is breastfeeding? Are food allergies preventable? Should we be worried about the aluminum in vaccines? Searching for answers to these tough parenting questions can yield a deluge of conflicting advice. In this revised and expanded edition of The Science of Mom, Alice Callahan, a science writer whose work appears in the New York Times and the Washington Post, recognizes that families must make their own decisions and gives parents the tools to evaluate the evidence for themselves. Sharing the latest scientific research on raising healthy babies, she covers topics like the microbiome, attachment, vaccine safety, pacifiers, allergies, increasing breast milk production, and choosing an infant formula.