The smartphone is one of the most useful creations of the last decade. For many of us, though, our use of them borders on compulsion. Adam Alter, a professor of psychology and marketing at NYU, joins us to talk about how the makers of smartphones and other products have cracked the code of behavioral addiction – and how we can gain control of our impulses. His new book is called “Irresistible: The Rise of Addictive Technologies and the Business of Keeping Us Hooked” (Penguin Press).