Kids' phone-based existence is 'inhuman' - and 10 times worse than any middle-school horrors: author

In fact, as he points out, teen girls are spending an average 20 hours a week - effectively a part-time job - on social media.

Haidt, whose book is out March 26, argues that smartphones and social media have contributed to a 'great rewiring' of childhood - causing sleep deprivation, social deprivation, attention fragmentation, addiction and spiritual degradation.

Read at New York Post