Lip Service

Smile, and the whole world smiles with you. But they don't all necessarily mean the same thing. Marianne LaFrance convinces us there's a secret wealth concealed behind that most common of facial expressions. Drawing from the allied fields of medicine, biology, psychology and anthropology, with a dash of computer science, LaFrance dissects the smile into its component parts and reassembles them into a potent force for both transparency and chicanery, friendship and enmity.

July 24: On this day in 1725 John Newton, the slave trader-preacher who wrote the hymn "Amazing Grace," was born.

Crime fiction legends Dennis Lehane and Michael Connelly discuss the new book that unites their beloved sleuths Patrick Kenzie and Harry Bosch.