I Don't Really Have Friends. Those "friends" Think I Consider

I don't really have friends. those "friends" think i consider them friends, but they are really not. they are just tools for me to get what i want. and so that other people know that i am actually capable of having friends. mostly I dont care about how they feel. one of them came up to me one day, and said that theor dog died the other night. I didnt really know what to say. I didnt care either. so i said. "i dont care" and they walked away crying. i cant really understand what these people are thinking when. I am nice to my friends because i want them to trust me when i want something from them. All I really cares about is myself. This is called something what is it?