Attached: The New Science of Adult Attachment and How It Can Help You Find—and Keep—Love by Amir Levine and Rachel Heller

As a romance author, I write about relationships so I am always a sucker for nonfiction books about relationships. This is an excellent one about attachment theory and the three types of attachment people experience—secure attachment (good news! most of us fall into this category), anxious attachment and avoidant attachment. Even if you're securely attached, the book's sections on how to interact with loved ones who are anxious or avoidant are very valuable–and a good reminder that sometimes you have to meet people where they are, not where you want them to be.