Climate change
You can add the climate emergency to the mass hysteria list. A new world science based on computer models programmed for free by post grads who know nothing about computer science using data that has to be massaged before it can be used. Any form of conclusion relies on data 100s of years old (short-term changes are meaningless) most of which does not exist and must be filtered and modified for "good" data - so much for controlled experiments.
Before the climate crisis no one was interested in climate science now 18 year olds want to study it in order to save the world. So most of these scientists who are filtering data and creating the computer models are climate change believers on a crusade to save the earth.
All you need to add is the population on mass simply repeating what everyone else is saying and calling that "understanding science" and some grown men crying because a penguin doesn't have to suffer as cold a winter as usual and you have all the ingredients of mass hysteria