I think it is a matter of individual choice. Something in their past triggers it. I don’t think there is a gene that causes it. I think it is mental/psychological. I knew someone exactly like this…the house was horrible and cat feces everywhere. Plus, they would continue to buy and buy and buy. It took her a while, but she started going to therapy. You wouldn’t believe the before and after look of the house. She had like 2,000 baby bottles she collected, books up to the ceiling, like 50 sheet sets, so much I can’t even begin.