Why Watching Silly Cat Videos Is Good for You” — Wall Street Journal:

“This type of online activity may feel silly and a waste of time. But a lot of what we do on social media may be good for us, a growing body of new research shows. Our experiences online can increase our connectivity and combat loneliness, boost our mood and improve our relationships and our memory.”

The article reports that neuroscientists believe we get a powerful positive reinforcement when we get a “like” or a comment on one of our posts. There is a spike of the neurotransmitter dopamine from the “like.”