With varying success, many women around the world today struggle for equal rights. Historically, women have achieved greater equality with men during periods of social adversity. Three of the following factors initiated the greater number of improvements for women: violent revolution, world war, and the rigors of pioneering in an undeveloped land. In all three cases, the essential element that improved the status of women was a shortage of men, which required women to perform many of society's vital tasks. We can conclude from the information in this passage that