I believe the answer is: normative history graded influences on human behavior
Cohort effects refers to a bond that created among a group of people after they are experiencing a similar experience. In society, different treatment toward a certain group is usually correlated to the event that happen in the past (normative history). For example, the racial tension that exist between 'white' and 'black' citizens in united states due to slavery.
Explanation:somatic nervous system is subdivided into motory nerves and sensory nerves that controls the voluntary movement of the body through the skeletal muscles.
