Yes, caste, creed, gender and colour divides people into small groups. These are the factors by which people are discriminated.
For eg--
1- If any good student is dark in colour then the other students might ignore him.
2- In studies in past the lower caste people were to sit on floor but the upper caste people were allowed to sit in the chairs.
3- Women are discriminated in past and were not allowed to study and were also not allowed to move out from there houses.