I remember reading about the scent thing; well not remember, I actually have it bookmarked. (Its like 4 pages long so I don't want to copy paste it xD)
But anyways, the scent thing is actually human nature. Here's a quote from an article
A segment of our DNA called the major histocompatibility complex (MHC) codes some diseases-detecting structures, which function as the immune system's eyes. When a disease is recognized, the immune system's teeth—the killer T cells—are alerted, and they swarm the intruders, smothering them with destructive enzymes. Unlike many genes, which have one or two alternative versions (like the genes that code for attached or unattached ear lobes), MHC genes have dozens of alternatives. And unlike earlobe genes, in which the version inherited from one parent dominates so that the version inherited from the other parent is not expressed, MHC genes are "co-dominant." This means that if a person inherits a version of an MHC gene for resistance to Disease A from its mother and a version lending resistance to Disease B from its father, that person will be able to resist both diseases.
Apparently a test was done, and people can in fact 'smell' differences in the MHC genes. If someone is vastly different than your own the smell is more attractive, and if its more similar it is less attractive.
Now normally I'd say this wasn't realistic, but its the second time i've seen this information (I just found it again, thus why i'm posting it) But its pretty interesting.
Anyways back onto to original topic, I have this weird habit of clawing things (not like a 'swipe' claw, more like a grab and puncture shoulder with nails claw)
Most people don't let me give them a pat on the back in case I latch on >.>