Doug’s Dime: Is your cellphone keep you up later?

A new study analyzing the cellphone use of adolescents found that on nights when teenagers used their smartphone for an additional 20 minutes in the hour before bedtime, they had eight to nine more minutes of late night use later that night. This makes sense; texts or posts that one sends before bed invite replies that must, by definition, come somewhat later. In general, pre-bedtime smartphone use was linked to greater late-night use; those in the study who averaged 20 minutes of pre-bedtime phone use had between 37 and 41 minutes of late night use, on average.