He is a "natural", in the sense that he can form close bonds with people incredibly quickly. At first I thought he was using some sort of secret strategy, but after a while I noticed that he was simply sharing personal details about himself (which the article refers to as "self-disclosure") without being prompted, which encourages, and in fact compels, the other side to reciprocate.
Here is an example conference call conversation from two weeks ago, in fact, in which we were chatting with a potential client to schedule a meeting. Bob is my boss:
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Bob: Okay. Let's have an in-person meeting next week. What day works best for you?
Client: How about Thursday at 2?
Bob: Sounds great. You know, I'm glad you didn't say Wednesday because I have to be with my two little girls that day, and I definitely could not miss that. They mean the world to me.
Client: Oh yeah, I understand. In fact I can relate... I have a daughter myself!
--
And then when we actually met in person this past Thursday, the topic of their daughters was a natural conversation point.
In contrast, I tend to be fairly reserved when it comes to sharing personal info. I like to stay on topic and dislike what I perceive as derails. The above conversation for me would have gone like this:
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Me: Okay. Let's have an in-person meeting next week. What day works best for you?
Client: How about Thursday?
Me: Sounds great. See you on Thursday at 2 PM.
--
Similar, but also very different.