Anybody who has been poor in Nigeria (note that I don't say poor in Africa because I know how irritating generalizations are) knows that they will do whatever is in their power to make sure that they are and everybody they love is never ever ever is in that situation again. This and the fact that there is no guarantee that you will receive your pension, or that the state will be there when you are sick, or will make sure that you have some electric light to read by, or some water to drink, that you will not get robbed of the little you have with impunity, and that you do receive even that which you pay for: the benefit of your taxes.
This to me is the basis of corruption among the average Nigerian.
I'm not talking about the leaders corruption, neither am I supporting or justifying corruption. I'm just trying to show its not as simple as it looks.
Why else would a policeman hold a man hostage over 20 naira?
Because to him, it may mean more than just 20 naira, it may mean meat in his soup that night.