We like people who like us (and state so publicly). We also like people are who are like us. Whether they share similar political views or hobbies, hail from the same part of the world or simply both smoke cigarettes, individuals with commonalities feel an affinity for one another.
I’ve heard the argument that respecting somebody is more important than liking somebody. Fair enough, but if you actually like that person, you’re more willing to consider his arguments more carefully, give him more time to communicate and be more receptive to his messages. Again, this is human nature; you just can’t help it.
The takeaway here? Be approachable, seek similarities and don’t be afraid to pay someone a compliment every once in awhile.