People that are not assertive frequently believe they have no right to their feelings, beliefs, and opinions. It is likely that their particular experiences of life have taught them to believe that their opinions and feelings are less important or correct than those of other individuals. Also, they do things in such a way that their negative views of themselves are confirmed as correct.
Lack of assertiveness is stressful because the individual discounts his or herself. There is a lack of belief in one's self and one's abilities; thus reducing the effectiveness of how one copes with life's stressors.
For more information see the
manual or the
training manual ( available in Arabic only)