where self image comes from

From http://talentdevelop.com/articles/IIGTBG.html (bolds mine):

Self-esteem can be thought of as the opinion we hold of ourselves. So where do we get this opinion? As children, we begin to develop a mental picture of ourselves in several different areas, including how we look, how we act, how popular we are, and how good we are at learning.

This mental picture is formed from early childhood through feedback we get from others and from comparing ourselves to those around us. The picture becomes clearer and more fixed as we get older, since our ideas about who we are get reinforced over time.

As we mature, we also develop a concept of an "ideal person," or how we "ought to be." These ideas are likely formed through messages received from sources around us like our parents, teachers, peers, and the media.

Our self-esteem, then, comes from comparing our mental picture of who we are to who we think we should be. Our feelings about ourselves can differ greatly according to what area of our lives we are considering and how we measure up to the ideal.