Here we have two sets of stereotypes. Stereotypes can be negative, like the first three stereotypes; or it can be positive, like the last two stereotypes.
With these examples given, it might be easier to explain what stereotypes really are.
Because the world is too big, too dynamic, and too complex for us as human being to understand it in all its detail, we have an urge to classify and categorize everything into compartments or pigeonholes. It is easier to handle and accept smaller groups, and it makes sense. The problem does not lie with this compartmentalizing or pigeonholing, it lies with the fact that we tend to overgeneralize these compartments. These overgeneralizations are often negative evaluations of these members of these compartments. For example, we know that all Africans are not black, and that there are rich and civilized black people. We also know that professors do make mistakes and that of their students are average, and that most foreigners in Thailand are not rich.
Stereotypes are learnt, just like culture. We learn stereotypes through socializing and observation, starting at home, with our parents and siblings, peer groups, community, religious groups, social groups, advertisements, the media, movies, etc. Some of these stereotypes are directly and consciously learnt, while other stereotypes are indirectly and unconsciously learnt.
Stereotypes can have its origin because people that look different, dress different, unknown religions, act and behave different to one’s own group.