It's a journal article title, not linkbait. Most scientific articles don't give away the ending, they're just a statement of what is. The idea presumably being, you must read at least the abstract

"proof" is not correct term. Find evidence supporting some hypothesis, they don't provide proofs.

That would have been a useful title. Even the payoff in the abstract 'Results from our analyses suggest that the observed association between education and mental health is attributable to confounding on unobserved variables.' would have left some people none-the-wiser.

We reset the title to that of the article, shortened to fit 80 chars.