A young colleague in Europe recently told me about some of the problems he has with students who don't treat him with respect. If he shows any sign of lenience, some students take advantage. Other students speak rudely to him.
This colleague is quite youthful looking and is not a large or imposing person. He is extremely nice and kind and thoughtful. It sounds as if some of his students are taking advantage of his niceness and others are testing him to see how he will respond.
In my younger days, I had some of these problems as well. Some of these negative interactions with students were very much gender related (example: A male student who was failing my course asked me if I ever walked alone on campus at night, and, if so, what my personal feelings were about rape. Did I think it was wrong? I found this conversation disturbing.) Other problems were more generic and are a particular affliction of those perceived to be vulnerable in some way: e.g., the youthful-looking and the non-tall.
The colleague in question is of course troubled by his negative interactions with some of his students, but I was troubled by the ways he has responded to these students or is planning to respond to some students. I think it is a mistake to overreact to such incidents or to show that you are very upset.
I did not give my young colleague direct advice because I think it would be obnoxious of me to say "You should do this and that" when I don't really know all the facts and I know little about the culture of his department or university. Also, I think that everyone needs to figure these things out in ways that best suit their own circumstances, personality, and philosophy. It can, however, be helpful to know how others have responded to similar situations, so I told him how I had or would respond in his position. He can use this information or not.
And that is: In these situations, my approach is to remain calm and consistent. It is possible to respond in a very firm and unambiguous way without appearing angry or upset. If the problems are extreme, the response can also be very strong, but showing well reasoned, patient, and persistent authority can be more effective than angry words. At least, this is what has worked for me in most situations of this sort.
Another colleague of mine used to react to student problems with great anger. She found that this was highly ineffective because some students responded by actively trying to make her angry, as if it were a game to see what buttons would get an angry response. This escalated into progressively more offensive behavior (example: Male students would show her obscene photos on their cell phones, just to see her get upset). Requesting help from administrators was not successful (their response: boys will be boys). It's difficult not to get angry in circumstances such as these, but when faced with such problems, I think a calm statement to the students of the (dire) consequences of their actions might work better than yelling. And then follow through with the consequences if required.
As college professors, we don't typically have to deal with the discipline problems of our K-12 teaching colleagues, but we do encounter student misbehavior of various sorts. We can't send these students to the principal or give them a time-out, so we have to use the tools at our disposal. Low-level rudeness can mostly be ignored or dealt with by discussion with the students. For more serious problems, it is worth looking into university policies regarding removing a threatening or disruptive student from a class or following other official courses of action.
6 years ago