Answer:
This is an example of longitudinal research.
Explanation:
Longitudinal research occurs when various subjects are studied through a long period of time, which can be weeks, months or years, amongst others. It can be used to find relations between variables, for example.
In this case, the researchers tracked individuals first during childhood to see their sleep rhythmicity and then their behavioral control during adolescence in order to make predictions regarding the subjects' adulthood.
