There as positively reinforced by comments from others

There are also sociocultural factors that
play into the development of an eating disorder, meaning that such factors
appear to play a role in the faulty perceptions and eating habits. Those diagnosed may
have maladaptive schemata that narrow their attention toward thoughts and
images related to weight, body shape and food. Within anorexia nervosa, the
emphasis on fears of fatness and body image disturbance are the motivating
factors that powerfully reinforce weight loss. Behaviors that achieve or
maintain thinness are negatively reinforced by the reduction of anxiety about
becoming fat as well as positively reinforced by comments from others (did you
lose weight? you look great!). Dieting and weight loss is also reinforced by
the sense of mastery or self-control they create. Some theories include personality and sociocultural variables in
an attempt to explain how fear of fatness and body-image disturbances develop.

For example, perfectionism and a
sense of personal inadequacy may
lead a person to become especially concerned with his or her appearance, making
dieting a potent reinforcer. Similarly, seeing portrayals in the media of thinness as an ideal, being overweight
and tending to compare oneself with these images all contribute to dissatisfaction
with one’s body. Another factor in producing a strong drive for thinness and a distorted
body image is criticism from peers and
parents about being overweight. When a person with anorexia nervosa
experiences a lapse in their strict dieting, the lapse is likely to escalate
into a binge. Emotions also play a role; people with anorexia deal with many
negative emotions. Although they also may experience a positive emotion such as
intense pride, after losing weight or avoiding eating a piece of cake at a
party. This may be indistinguishable from happiness or success and is referred
to as low positive emotion differentiation.