Thoughts that trigger emotional responses in the body may sometimes come so fast that before the mind has had time to voice them, the body has already responded with an emotion, and the emotion has turned into a reaction. Those thoughts exist at a preverbal stage and could be called unspoken, unconscious assumptions. They have their origin in a person's past conditioning, usually from early childhood. "People cannot be trusted" would be an example of such an unconscious assumption in a person whose primordial relationships, that is to say, with parents or siblings, were not supportive and did not inspire trust.

Eckhart Tolle

from A New Earth: Awakening to Your Life's Purpose