Technically, humans can have no social skills, then build them. For instance the Russian (or whatever) girl who was "raised by dogs" and then eventually brought into a foster home. Humans are social animals by nature. It is possible to have low social skills while others have very high social skills. It's like a gradiant scale.
Yes, I never feel like I have anything to say. My interaction is usually dependant upon the other person, how well they seem to recieve me and if I feel comfortable opening up to them (if ever). Most people I get by on the bare minimum. I think I have trust issues so I just have this fear/insecurity/arrogance which makes me just avoid interacting all together. (I included arrogance just because I usually presume the energy/worry isn't worth the interaction with the other person.) Even on the internet.