So, correct me if I'm wrong, but I remember you mentioning at some point that you have a degree in psychology? And I personally don't know enough about psychology to answer this for myself, but... exactly how much can a person feasibly change as a result of traumatic circumstances?
I ask this because there was a discussion on the Animorphs subreddit about a certain rat we all love to hate, and how much the way he acts is a result of what he'd been through. I was (and still am) of the opinion that he was already a little shit before all that, and while I'm pretty sure I could find evidence for that in canon already, I am also of the opinion that he would have never reached the levels of petty vindictiveness and even downright sociopathy that he does if that hadn't been the case. But someone else insisted that it was not only possible, but also incredibly likely, for someone's personality to do a complete 180 after experiencing that much stress/trauma.
It's a doorstop, but I recommend Behave: The Biology of Humans at our Best and Worst by neuroscientist Robert Sapolsky. He talks about how:
There are people who seem to be able to do the right thing no matter their circumstances — his example is the soldiers who stopped the My Lai massacre, even though it cost them their careers and sometimes their lives.
There are people who seem to be selfishly inclined no matter their circumstances — his example is disaster capitalists, rushing to capitalize on mass murder for profit.
And then there's the rest of us, who spend our lives trying to figure out what the right thing is and how to do it. Sometimes we have an opportunity to rise to the occasion and do the right thing in a spectacular fashion, but rushing into housefires to save kittens is a Hollywood-blinded view of what goodness means and if you drive around looking for flaming kittens you'll never have the chance to provide a meal for a neighbor in need.
He goes into depth about John Newton, the enslaver turned abolitionist who wrote "Amazing Grace," and how this is a guy who clearly spent his entire life trying to figure out how to be a good person, constantly messing it up. Part of what Sapolsky emphasizes is that the narrative "Newton enslaved people, then he got captured and enslaved himself, then he got ransomed and became an abolitionist" is massively oversimplified. We see Newton struggling with the morality of slavery from his earliest childhood writings, but he went on to profit from the slave trade anyway. He continued to enslave people for a few years after being himself enslaved, until he figured out how to become an effective abolitionist. He struggled his entire life with these questions, and what he ultimately needed were opportunities to be good.
So: assuming John Newton is a decent case study for what most of us are like, I don't think that anyone's entire personality switches from selfish to selfless as a result of a single experience. I think that learning is important and possible, that there's more potential for learning to have a lasting impact the younger you are when the learning happens, and that life-changing experiences tend to be learning experiences. However, whether a person learns "I should have been better, because I behaved selfishly and now look at the consequences" or instead learns "other people are awful, because I was just looking out for myself and now look at the consequences" probably depends on their capacity for self-awareness. Which one David gets out of the experience of being an Animorph is probably down to your interpretation of David.
