The "scripts" I think come from many things. One is hormones as GiveLove stated. Another is that mental health issues do indeed follow some set patterns. So those who are codependent follow the script that goes along with that. Those who are ACOA follow the script that goes with that. Those who are battered spouses follow their script. Now within these labels there is also wide variation in the individual's behaviors and the degree to which they follow the script. All these scripts interact with each other. And then you can throw in the general societal scripts based on being male or female.
Whew, there are a lot of scripts we all follow from this way of looking at it (and its only valid to a point). At least we follow them until we learn to recognize when we are following the script and start tearing the script up so that we aren't acting in that unhealthy way and learn to write our own healthy script.