In psychology, an inferiority complex is an intense personal feeling of inadequacy, often resulting in the belief that one is in some way deficient, or inferior, to others.
According to Alfred Adler, a feeling of inferiority may be brought about by upbringing as a child (for example, being consistently compared unfavorably to a sibling), physical and mental limitations, or experiences of lower social status (for example, being treated unfavorably by one's peers).
An inferiority complex may cause an individual to overcompensate in a number of ways. For example, a person who feels inferior because they are shorter than average (also known as a Napoleon complex) due to common day heightism may become overly concerned with how they appear to others. They may wear special shoes to make themself appear taller or surround themselves with individuals who are even shorter than they are. If this is taken to the extreme, it becomes a neurosis.
It may also cause an individual to be prone to flashy outward displays, with behavior ranging from attention-seeking to excessive competitiveness and aggression, in an attempt to compensate for their either real or imagined deficiencies.