Hacking oneself to be polyamorous seems itself like preference rather than behavior hacking, which is why I'm confused. I would have to change what I want out of relationships to become uncomfortable with being in romantic relationships containing more than two people (my case is a bit more complicated than that, there are different types of polyamory, but the specifics aren't relevant to the main point.) Similarly, I find it doubtful that a person hard wired for monogamy (and some people seem to be intensely monogamous by nature,) could be hacked into polyamory without altering their values with regards to relationships.