According to Batson (1991), when people experience empathy for another in need, they will help.
Shoulders i think im pretty sure
Answer: Parallel processing
Explanation: Parallel processing is the brain's ability to process or do many things (perform alot of task) at the same time. A typical example is when you see a person, first you see the color of the skin, the height, shape of the body or face (eyes, nose, ear mouth, jawlines); you brain process this information at the same time and it instantly recognizes the person to be either a family member, a friend, a total stranger etc.
Back then african had huge amount flooding and disaster which affect the farming planting crop hardly time. Now overtime thing change and african had increase tool and other etc... which help them. They also use trade route to trade other nation goodies that increase profit rich