Validation is the recognition and acceptance of another person's thoughts,feelings, sensations, and behaviors as understandable. Self-validation is the recognition and acceptance of your own thoughts, feelings, sensations and behaviors as understandable.
understanding the person's behavior in terms of their history and biology. Your experiences and biology influence your emotional reactions. If your best friend was bitten by a dog a few years ago, she is not likely to enjoy playing with your German Shepherd. Validation at this level would be saying, "Given what happened to you, I completely understand your not wanting to be around my dog."
Self-validation would be understanding your own reactions in the context of your past experiences.
It's about accepting someone's internal experience as valid and understandable.
Emotional invalidation is when a person's thoughts and feelings are rejected, ignored, or judged. Invalidation is emotionally upsetting for anyone, but particularly hurtful for someone who is emotionally sensitive.