Spoiler it's almost, if not always - fear. "If I understand why my children are lying to me, if I can go ok, what are they afraid of, what's going on here, I am able to shift the environment so that I can become a safe person, that can hold and handle the truth, without creating that fear response...
Maslow’s Hierarchy of needs
https://www.simplypsychology.org/maslow.html
