[xparadigm]

In my experience, it comes down to matching patterns.

Here's what I think likely happened: your friend talked to other people who went through tragedy. He noticed something common in their behavior. It can be something so subtle that it's invisible to most people, but your friend notices these kind of things. Then when he talked to the current person, he found the similar pattern.

[RajT88]

Ah, but some people have more attitude for perceiving those patterns in the first place.

I imagine the author of this article is describing something along the lines of my friend's cognitive capabilities.