I don't really like people. I might enjoy spending time with them. I might care for them a great deal. I might want to be their friend or do what I can for them. I might have sexual feelings for them. But I just don't have genuine affection for people. When people start to get close to me, I'll shut them out.
When I was young I received a great deal of hazing, teasing, bullying, etc. by people who I had affection for, so I think my succorance has just become completely inhibited by my fear of rejection.
So I generally pretend to like people. It has the same affect as the study mentioned in the OP. But when they start to show geniune affection to me beyond just friendship, I distance myself from them.