A very large study of 55,00 europeans from childhood through late adulthood found that eveningness peaked at what age?

Based from a huge study that was done with 5,500 respondents who lived in Europe from childhood through late adulthood found that eveningness peaked at ages a. 20 to 21 years.

The study's results mean that a lot of people are in the stage of peak alertness during the age of 20 to 21 years old. This age is the stage of a person's life where they are in the young adulthood stage.