CAVEAT: I am not a doctor, psychologist, or even counselor. These are my own musings.
Humans, by their very biology, are social creatures. Even loners need some form of physical interaction.
Babies, if they are not touched and held enough, will fail to thrive just as surely as if they are not being fed enough.
When a mother holds her child, or a lover their beloved, oxytocin is released. Oxytocin is called the bonding hormone for good reason, as it promoted prosocial behaviors.
As children grow, physical interaction is still very important. From diaper changing to owie-kissing, it shows love in myriad ways.
So what happens when the child continues to age, but now, instead of playing outside with friends, they are shut inside… Alone… With a screen? What happens when the child is left to take care of their own need for interaction?
When what might have been a neurotypical (“normal”) person is deprived of the very thing that indirectly affects social behavior, they become antisocial. Sure, they have “friends” online through that screen, but those “friends” are no more real than HAL 9000 in 2001: A Space Odyssey. They cannot reach through the screen and hug or touch.
So, basically, we have a different kind of failure to thrive, children that are aging without actually growing up. School can help, but it can only do so much; and overscheduling children in extracurricular activities can foster resentment.
So then a child has no, or few, “In Real Life” friends; basic needs (such as love and attention) are neglected; and they spend too much time with glamorized video games and television shows. Perhaps they learn that they are “unworthy” of love. After all, the celebrities are getting married and hanging out with their entourage of friends, or they see the “perfect family” with hugging and family activities. But there’s this void, that needs to be filled, and there is no entourage of friends, or family interaction. Obviously it is their own fault.
Antisocial behavior and exclusion can lead to depression and rage. Just as a toddler cannot control their behavior, this person who has been deprived of that “switch” inside the brain that turns on and off depending on the hormonal bonding surge. A toddler can learn, given guidance and attention; but this child is “stuck”. And the more antisocial the child is, the less inclusion there is, until there is a break, and the child acts out for a little attention.
Toddlers throw tantrums for attention. As they get older, they learn better ways of gaining attention; but not a deprived child. A deprived child throws a tantrum that is larger in scale, may be premeditated, and due to their increased knowledge, may involve deadly weapons.
This is all speculation, but I know that there have been major societal changes with the advent of less expensive, more easily accessible technology. Not all of them are for the good.