The paradigm has shifted. Dating is dated. Hooking up is here to stay. ... To help me understand this phenomenon, I called Kathleen Bogle, a professor at La Salle University in Philadelphia who has studied hooking up among college students and is the author of the 2008 book, “Hooking Up: Sex, Dating and Relationships on Campus.” It turns out that everything is the opposite of what I remember. Under the old model, you dated a few times and, if you really liked the person, you might consider having sex. Under the new model, you hook up a few times and,...