For kids, part of the process of becoming a teenager means identifying less with family, more with friends (of both the same and the opposite sex). This breaks parents' hearts a little—because it means they talk mostly to one another and very rarely to us. This is not exactly news. It's been going on for millennia, and every society has coped differently.
However, to paraphrase an ancient Chinese curse, today's moms and dads are doomed to live in interesting times. The past few decades have brought about major technological leaps in terms of telecommunications. Teens in the 1950s and 1960s were gifted with the meteoric rise of the telephone, an innovation that changed adolescent relationships forever, even if they had to chat in the hall within earshot of everyone. The 1970s brought phones in their bedrooms, altering the dynamic again. Fast-forward to the 1980s, when teens were spending so much time talking, exasperated parents had second lines installed. E-mail ushered in the 1990s, followed by instant messaging. The walk-up to Y2K brought cell phones. And today's teenagers, luxuriating in their own personal slice of telecom history, have texting.