I like my personal space, and, well, since the article violated my perceived personal belief space, of course, flight-or-fight response was triggered; you can see the outcome pretty clear I suppose. It was not "fear".
I get that "space spaces" and "personal space" both have the word "space" in it. But if we're discussing scientific studies, it's not constructive to compare the two. Unless you have something really substantial (and accurate) that adds to the conversation, I think it's time better spent to discuss the article at hand.
I personally think it's a fascinating insight into how humans interpret physical space and the implications in social situations.