Stereotypes. Gender, race, ethnic, religious, yada yada yada. Many more to choose from.
Any truth to them? In a general sense.
1) Yes, stereotypes are generally pretty accurate.
2) Stereotypes are generally founded in truth, but have also generally become outdated.
3) Occasionally, but seldom, accurate.
4) No, stereotypes are a bunch of crapola.
Keep in mind that the question is generic and overall in nature. A single anecdote, or your close friend's brother-in-law's barber's experience as an exception to the general rule does