Book excerpt: From a noted science journalist comes a wonderfully witty and fascinating exploration of how and why we kiss. When did humans begin to kiss? Why is kissing integral to some cultures and alien to others? Do good kissers make the best lovers? And is that expensive lip-plumping gloss worth it? Sheril Kirshenbaum, a biologist and science journalist, tackles these questions and more in The Science of a Kiss. It's everything you always wanted to know about kissing but either haven't asked, couldn't find out, or didn't realize you should understand. The book is informed by the latest studies and theories, but Kirshenbaum's engaging voice gives the information a light touch. Topics range from the kind of kissing men like to do (as distinct from women) to what animals can teach us about the kiss to whether or not the true art of kissing was lost sometime in the Dark Ages. Drawing upon classical history, evolutionary biology, psychology, popular culture, and more, Kirshenbaum's winning book will appeal to romantics and armchair scientists alike.