alt Hacker News> A much more plausible causal explanation
Why is that much more plausible? It implies that it has always been there, and that nothing has changed since the last century, which is unlikely. Unless you want to introduce some other recent factor, but that is going to be even less likely.
And why? Because other studies have shown how addictive "phone" use is, and how it isolates people. And addicts (drugs, alcohol) are bad caretakers.
So there's really nothing that makes the explanation implausible.
You may ask yourself if it's not your own addiction speaking.
I find it more plausible given my priors as a research psychologist.
Correlational overlap between self-report scales is common. It's actually so common that at decent sample sizes, almost any arbitrary self-report will significantly correlate purely on valence. For instance, one should expect a correlation between people self-reporting "I had a tough childhood" with "I frequently suffer from skin rashes". This is because trait neuroticism (the degree to which people are prone to feel negative emotion) is a major driver of how people interpret and respond to scales generally.
In contrast, psychologists mightily struggle to find replicable experimental results. That's what you need here.