section_path: Theories of motivation/Demographic/Youth bulge
section_name: Youth bulge
paragraph_text: Youth bulge
  
  According to Heinsohn, who proposed youth bulge theory in its most generalized form, a youth bulge occurs when 30 to 40 percent of the males of a nation belong to the "fighting age" cohorts from 15 to 29 years of age. It will follow periods with total fertility rates as high as 4–8 children per woman with a 15–29-year delay. Heinsohn saw both past "Christianist" European colonialism and imperialism, as well as today's Islamist civil unrest and terrorism as results of high birth rates producing youth bulges.
  
  Among prominent historical events that have been attributed to youth bulges are the role played by the historically large youth cohorts in the rebellion and revolution waves of early modern Europe, including the French Revolution of 1789, and the effect of economic depression upon the largest German youth cohorts ever in explaining the rise of Nazism in Germany in the 1930s. The 1994 Rwandan genocide has also been analyzed as following a massive youth bulge. Youth bulge theory has been subjected to statistical analysis by the World Bank, Population Action International, and the Berlin Institute for Population and Development. Youth bulge theories have been criticized as leading to racial, gender and age discrimination.