Basically Adam was intimidated by this thing and failed to protect Eve from it, she was convinced to eat the fruit, and Adam then went along with it like a wuss.
I think it was deception rather than fear.....hath God said, Ye shall not eat of ANY tree in the garden? (question, raises a point with a sujestion ANY (lie). Eve (vs2) Eve answers not out of ignorance but knowing the God said only one tree.
(vs 5) the enticement
It was her own desires she dwelt on and therefore after giving into them she became independant of God, deciding for herself, becoming a law unto herself. Adam choose Eve over God therefore abandoning his headship role, this is why the headship is enforced in such an unloving harsh way, so as not to loose control, of the women. Without God governing their lives everthing is extreme and unbalanced.
Satan used Eve because she was the youngest most vunerable (spiritually) we don't know how long after Adam was created Eve was. So the difference in experience and spiritual maturity, really was the key, so Eve was tricked (decieved) and Adam made a conscience decision and choose the women over God. They came under the headship of Satan. Just my view.