Discussions

Ok, so I was helping a tenant move out of one of my properties. And when moving her matress I noticed it was covered with signatures-or names of guys. I was a bit shocked. But I remembered a research paper I had read related to this topic and it suggested that some women do journal the men they sleep with in an attempt to gain self-confidence, enhance feelings of attractiveness,desirability, etc. And I am wondering how common is this act? Is it generally women? Why is it done? I am looking for some research material here, please give me some input.