When something we perceive as negative occurs, we notice it. We notice it more than when something positive happens. Many studies show that we will look at something negative for longer than something positive. You just have to drive past an accident to realise this. We notice all the red lights and bad driving out on the road more than we notice the green lights and polite driving. Negative and extreme content goes viral more than positive content. I think there's a connection between this and our deteriorating mental health.