Final answer:
Age-graded influences refer to events or experiences that are common and expected at particular ages. History-graded influences are events or experiences that are unique to a specific historical period. Nonnormative influences are events or experiences that are uncommon or unexpected.
Step-by-step explanation:
Age-graded, history-graded, and nonnormative influences are three types of influences that shape human development. Age-graded influences refer to events or experiences that are common and expected at particular ages, such as starting school or retiring. History-graded influences are events or experiences that are unique to a specific historical period, such as going through a war or living through a pandemic. Nonnormative influences are events or experiences that are uncommon or unexpected, such as winning the lottery or experiencing a natural disaster.