Because it is a common perception that some physical attributes is associated with certain characteristics.
For example, obesity usually associated with laziness and unassertiveness because of most people aware that it took discipline to obtain good body.
But on the contrary, people also usually associate obese people with kindness and heartwarming nature
Answer:
because people in rural areas are more involved in physical work like agriculture, grazing animals, fishing etc. Such work needs more physical labour and hence more calorie intake is demanded.
Biopsychological is your answer .-.