Concrete Operational stage
Formal Operational stage
To find out about the importance of body contact
To find out about the length of the critical period
To find out about imprinting
To find out about what food the monkey eats
To find out how quickly they develop psychologically
It is the longest period in our sleep cycle.
REM rebound occurs everyday, representing that it is important.
Since REM sleep increases when sleep deprived, it shows that body needs REM sleep.
It prevents one from dreaming, which is harmful to one's health.
It portrays one's latent content and manifest content of the dream/
Law of effect