The worst impact of colonialism in Africa is that they divided people by ethnic groups. I think it's the worst because you may be the same ethnicity, but you may have different beliefs. Which causes a problem. It starts an argument. You may believe in this God and the other may believe in a different God. It's not good to do this. A lot of people would hate to have to live with the people they aren't like. They want to be with the people they share common intrests with. I know I wouldn't like it.