I reject the previous assertion that differences between individuals are predominantly software rather than hardware.

I think we may agree more than you think. I agree that individuals are different in terms of whatever dial settings they may have when they show up at my door. I disagree that those initial dial settings are welded in place and not changeable.

"Hardware" and "software" are squishy terms when it comes to brains that can not only learn, but literally grow. And ISTM that most homeostatic systems in the body can be trained to have a different "setting" than they come from the factory with.