I've been using CSS since it first [barely] appeared in IE3, but I've been behind on fully getting to know flex and grid. Didn't know about aspect-ratio at all.
Maybe that says more about the amount of attention I've been paying, but I learned a lot from these examples.
> virtually every other person is radioactive to you.
While you're not wrong, this behaviour is already present - just randomly distributed. Some/many people withdraw, interact with fear, maybe eventually get fed up and take risks, based on guessing-games.
If this research proves fruitful, it will reduce the guesswork a lot, and people can try to find more practical and constructive approaches.
I'm not aware of HN doing any predicting at large. If you mean 'will the average person later act like a given segment of HN people do now?' - then it depends on how good you are at selecting your segment, which makes it no better or worse than using any other sample of people for prediction.
Less abstractly, productisation is what takes things from obscurity (e.g. HN) to mainstream audiences, so future trends might grow out of stuff that you see here, but the people who can figure out whether certain tech can become a product (would-be predictors) -hopefully- also have the means to turn it into a product themselves.
Because of the filesize, this would be right at home on the 512KB club: https://512kb.club/