I find it increasingly difficult to talk about the human fall in a secular culture by using scriptural justifications. The Divine Principle is a book written in the language and culture of Judeo-Christian thought, but the language of our current culture is more shaped by universities than by churches. I have found audiences show greater understanding of concepts like the Fall when using terms from social psychology.
Reaction and integrity
My basic position is that reaction is a characteristic of the growth stage and integrity is characteristic of the perfection stage or maturity. Adam and Eve were given a commandment “not to eat of the fruit” when they were children because they did not live in a state of integrity, and were subject to impulsive reactions. Adam and Eve fell at the top of the growth stage through such a reaction and disobeyed the commandment. If they had reached integrity they would understand the consequence of their actions and would not have acted blindly. Obeying the commandment would have kept them on course so they could each grow to maturity and be in a position to raise children from integrity before consummating their marriage.
The concept of “cognitive dissonance” can help us understand the motivation for the human Fall. Cognitive dissonance is when we expect one thing based on our beliefs and understandings, but experience something else. Cognitive dissonance causes frustration and is uncomfortable.