Does the presence of high level trainers have an effect on low level ones? [duplicate]

From my own experience and that of people I know, your level affects the CP value of Pokemon you encounter, not necessarily the Pokemon themselves. So, if one of you is level 15 and the other is level 5, you will both encounter the same Pokemon in the same locations, but the level 15 might encounter a CP 500 while the level 5 might encounter a CP 50.

I don't know if this is enough to confirm it but a post does state that rarer pokemon appear the higher level you are: http://www.forbes.com/sites/davidthier/2016/07/12/how-to-find-rare-pokemon-in-pokemon-go/#14fd4e764cbb

From personal experience I am also inclined to agree but keep in mind more populated areas also tend to have more pokemon variety. As to answer your question directly everyone sees the same pokemon near them so I do believe that your presence does actually have some effect but it should still be rather minimal. I don't know if a pokemon have a minimal CP level but if they do and the minimal CP level is above the max CP level a trainer can see then she shouldn't be able to see it, but that's just speculation.