I definitely think they do. As soon as I get home mine are waiting at their doors wanting scritches. When I let Lily out to play she'll popcorn around my feet for a minute, but she won't do that when my boyfriend lets her out. Also, if I put my nose to her cage she'll groom it and make happy squeaks at me. When my boyfriend is sitting in his recliner Donna will climb up to his shoulder and start grooming him and making chin greeting noises (I tease him that she's got a crush, cause she never does it to me). All of these are examples of repeated behavior, and because the girls show preference to one human over the other I don't think it's just bravery or inquisitiveness. I've owned a wide menagerie of pets throughout my childhood, and I'd say that chins are a very intelligent species compared to some. Lily is actually trained to respond to a few voice commands, and I know many people on the forum have their chins potty trained. With this kind of intelligence I think they are also capable of showing preference or affection to humans as well as other chins.