Napoleon complex is an informal term describing an alleged type of psychological phenomenon which is said to exist in persons, usually men, of short stature. It is characterized by overly-aggressive or domineering social behavior, and carries the implication that such behavior is compensatory for the subjects' stature. The term is also used more generally to describe people who are driven by a perceived handicap to overcompensate in other aspects of their lives. Other names for the term include Napoleon syndrome and Short Man syndrome.  It does not appear in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders (DSM).
The Napoleon complex is named after Emperor Napoleon I of France. The conventional wisdom is that Napoleon compensated for his lack of height by seeking power, war and conquest. However, Napoleon was actually above average height for his time period; the average 18th century Frenchman stood at 5 ft 3 in (1.6 m). Historians have now suggested Napoleon was 5 ft 6 in (1.68 m) tall. Napoleon was often seen with his Imperial Guard, which contributed to the perception of his being short because the Imperial Guards were above average height. In psychology, the Napoleon complex is regarded as a derogatory social stereotype.
In 2007, research by the University of Central Lancashire suggested that the Napoleon complex (described in terms of the theory that shorter men are more aggressive to dominate those who are taller than they are) may be a myth. The study discovered that short men (below 1.65 m (5 ft 5 in)) were less likely to lose their temper than men of average height. The experiment involved subjects dueling each other with sticks, with one subject deliberately rapping the other's knuckles. Heart monitors revealed that the taller men were more likely to lose their tempers and hit back. University of Central Lancashire lecturer Dr Mike Eslea commented that "when people see a short man being aggressive, they are likely to think it is due to his size, simply because that attribute is obvious and grabs their attention."
The Wessex Growth Study is a community-based longitudinal study conducted in the UK that monitored the psychological development of children from school entry to adulthood. The study was controlled for potential effects of gender and socioeconomic status, and found that "no significant differences in personality functioning or aspects of daily living were found which could be attributable to height"; this functioning included generalizations associated with the Napoleon complex, such as risk-taking behaviors.
Professor Abraham Buunk of the University of Groningen in the Netherlands has found evidence of the small man syndrome. Researchers at the University found that men who were 1.63 m (5 ft 4 in) were 50% more likely to show signs of jealousy than men who were 1.98 m (6 ft 6 in). Sociological experiments have shown that there are several advantages to being tall in attracting a mate, and the small man syndrome is believed to be an evolutionary adaptation.
In evolutionary theory 
The term "Napoleon complex" has been used in scientific research on the phenomenon of smaller organisms acting aggressively towards larger organisms. In contrast to the many examples of larger organisms acting aggressively towards smaller organisms in the animal kingdom, some studies of aggressive behavior in organisms have detected cases where smaller individuals initiate aggression. A 1995 study of contests between males in the swordtail fish species Xiphophorus nigrensis and Xiphophorus multilineatus found that 78% of observed fights were initiated by the smaller fish, and in 70% of fights the fish that delivered the first bite lost the conflict. From an evolutionary perspective, this "Napoleon complex" behavior seems irrational.
Posited explanations include an asymmetry in the value of the contested resource to the two combatants (the individual with lower resource holding potential may attack first if the value of the resource is greater for him), a misconception on the part of the weaker organism about his own strength, and the "Desperado Effect", where omega males attack because they have no other opportunities to gain resources.
Ohio University researchers have suggested another explanation, that the stronger contestant benefits from delaying escalating a display to a fight, "leaving the initiative to the opponent and hoping for him to retreat, either because of realistic perception of his chances to win the fight or by mistake. [...] our proposed explanation for what is commonly considered the 'Napoleon Complex' might be appropriately identified as the 'Gentle Giant Syndrome.'"
A University of Leeds study concluded that a Napoleon complex evolutionarily stable strategy, where smaller individuals are more aggressive than larger opponents, is possible when smaller individuals display and larger individuals retreat; this may occur when the smaller individual has some chance to win a fight and resources are abundant and of relatively low value, or when the value of the resource is too small to the larger individual when compared to the injury risk.
See also 
- Morrison, Richard (2005-10-10). "Heart of the Fifties generation beats once again". The Times. Retrieved 2008-01-17.
- "Short men 'not more aggressive'". BBC News. 2007-03-28. Retrieved 2008-01-17.
- The Diagnostic and Statistical Manual published by the American Psychiatric Association
- "Napoleon's Imperial Guard".
- Sandberg, David E.; Linda D. Voss (2002-11-27). "The psychosocial consequences of short stature: a review of the evidence" (PDF). Best Practice & Research Clinical Endocrinology & Metabolism (Elsevier Science Ltd.) 16 (3): 450. Retrieved 2008-01-01.
- Ulph, F.; Betts, P; Mulligan, J; Stratford, R. J. (January 2004). "Personality functioning: the influence of stature". Archives of Disease in Childhood (BMJ Publishing Group Ltd) 89 (1): 17–21. doi:10.1136/adc.2002.010694. PMC 1755926. PMID 14709494.
- Lipman, Terri H.; Linda D. Voss (May/June 2005). "Personality Functioning: The Influence of Stature". MCN: the American Journal of Maternal/Child Nursing (Lippincott Williams & Wilkins) 30 (3): 218. doi:10.1097/00005721-200505000-00019.
- Short man syndrome not just a Tall Tale. http://www.telegraph.co.uk/earth/earthnews/3336044/Short-man-syndrome-is-not-just-a-tall-story.html
- Morrell, Lesley J.; Lindstrom, Jan; Ruxton, Graeme D. (2005-06-15). "Why are small males aggressive?". Best Practice & Research Clinical Endocrinology & Metabolism (The Royal Society) 272 (1569): 1235–1241. doi:10.1098/rspb.2005.3085. PMC 1564107. PMID 16024387.
- Just, Winfried; Morris, Molly R. (September 2003). "The Napoleon Complex: why smaller males pick fights". Evolutionary Ecology (Kluwer Academic Publishers) 17 (5–6): 509–522. doi:10.1023/B:EVEC.0000005629.54152.83. Retrieved 2008-01-01.
- Just and Morris, 511.
- Just and Morris, 518.