Children who extensively use smartphones are markedly unhappier according to a study exploring the link between adolescent life satisfaction and screen time. To investigate this link lead author and San Diego State University and professor of psychology Jean M. Twenge along with colleagues Gabrielle Martin at SDSU and W. Keith Campbell at the University of Georgia crunched data from the Monitoring the Future (MtF) longitudinal study a nationally representative survey of more than a million U.S. 8th- 10th- and 12th-graders. The survey asked students questions about how often they spent time on their phones tablets and computers as well as
