If you say 'a correlation exists between X and Y' yes. If you say 'X is linked to Y' most people will assume they're positively correlated, in line with the positive sentence structure. I too drew the opposite inference from the HN headline to the actual result of the study.

I agree but I thought the same thing. "Linked" sort of tacitly implies a positive correlation, not a negative one, I think.

Then a better word choice would be "lack of interest" or "uninterest"...