People who lived through the great depression may perceive resources as being scarcer than others do. this is an example of how the affects perception.

cohort effect

Explanation:

The cohort effect refers to characterestics or divergencies shared by people treated as a group, who have gone through or share certain experiences, such as having the same age or background, or undergo similar situations or events. Consequently, people who have experienced extreme circunstances like the Great Depression may perceive supplies, money and possessions as insufficient and limited.

permafrost layer, it exists beneath a layer of soil, rock or sediment.