When I was at school, one of the things that my English teacher would tell us was that we shouldn’t use the word nice. He considered it bland and thought that there were more descriptive words that better expressed what something was like. However, I think that nice can be extremely good at times, especially when you are considering your interactions with other people.
Why should you be nice?
The world of academia/work is quite small and it is likely that anybody you meet once you will meet again if they remain in the same area. However, when we next meet them they could be in another job or publishing work we find interesting. If this is the case then they are probably someone you want to talk to and potentially collaborate with. However, if when you met them the first time you were rude or brusque, then they may remember this and be less inclined to spend time with you. As the cliché says “what goes around, comes around”. Conversely, if you were pleasant when you first met them or provided help or advice they will remember you favourably, and good things may come from the next meeting.
Surely this is a cynical approach to the world
This may be considered cynical, however, it is also a valid approach to life, and if you start making a conscious effort in this, it will eventually become a habit. Furthermore, if you are consistent you may develop a reputation as a helpful individual who is good to know and opportunities may come your way that you were not aware of.
A very good discussion on this appears in the book Have Fun, Get Paid: How to Make a Living with Your Creativity. This book focusses on creativity and creative industries, however, I feel it is applicable beyond this area and would recommend it.