Answer:
Biological perspective.
Step-by-step explanation:
Biological psychologists area of interested is the measure of biological, genetic or phsysiological variables to try and relate them to psychological or behavioural variables. In the example, a group of psychologists are studying how certain parts of the brain allow people to distinguish between positive and negative emotions. They are studying a biological and phsysiological variable to relate it to a psychological one, an emotion.