Differences do exist between people, but dwelling upon them is a dangerous process. Unless carefully handled, it leads directly to egotism.
Ordinary human thinking is full of greed, jealousy and pride. A man seeing another man on the street may immediately think, "He is better looking than I am." The instant result is envy or shame. A girl seeing another girl may think, "I am prettier than she is." The instant result is pride. This sort of comparison is a mental habit, and it leads directly to ill feeling of one sort or another: greed, envy, pride, jealousy, hatred. It is an unskillful mental state, but we do it all the time. We compare our looks with others, our success, our accomplishments, our wealth, possessions, or I.Q. and all these lead to the same place--estrangement, barriers between people, and ill feeling.