Final answer:
The one-child policy in China has led to a major gender imbalance due to cultural preferences for male children and the enforcement of the policy. This has resulted in sex-selective abortions and female infanticide, leading to a larger number of males than females in China. Other factors like sexist cultural attitudes and government policies can also contribute to imbalanced sex ratios in different countries.
Step-by-step explanation:
The one-child policy in China was implemented to address population growth and its related environmental, economic, and social issues. However, the policy has led to a major gender imbalance due to cultural preferences for male children combined with the enforcement of the policy. This has resulted in sex-selective abortions and female infanticide, leading to a larger number of males than females in China.
Besides the one-child policy, other factors like sexist cultural attitudes, wars, and government policies can also contribute to imbalanced sex ratios in different countries. For example, in China, traditional gender notions and the one-child policy have significantly reduced the number of girls born, resulting in an expected surplus of nearly 30 million men by 2020.
The negative consequences of gender imbalance include societal challenges like a shortage of women, leading to increased competition among men for marriage partners and potential social unrest. Additionally, imbalanced sex ratios can have other significant impacts on societies, including increased crime rates and population growth.