Teens constantly connected, increasingly unhappy

Technology will not necessarily make your kids fat, dumb or mean. (Common Sense Media/TNS)

Jean Twenge had never seen anything like it. The San Diego State University professor in personality psychology had been studying generational differences for 25 years, since she was a 22-year-old PhD student at the University of Michigan. Her research had generated more than 120 scientific publications. 

In 2012, when the proportion of Americans who own smartphones surpassed 50%, she noticed abrupt changes in teen behaviour and emotional states.