just be respectful, hardworking, show up on time, stay until the work is done, don't be argumentative, take the high road and don't get in pissing contests, etc... in other words just be professional. no one owns your mind, and no one wants to. but people who get along with others, even if some of the others are difficult, are the ones who are most successful in any field.
as for gs specifically... understand that before you get to the point where you can challenge senior residents, and attendings, you have a lot to learn. when you learn the basics, and have established a strong professional reputation for yourself, then you are more likely to be taken seriously by the chief resident, or the attending when you have a difference of opinion. stay humble, and work hard. if you are a compassionate, professional, person then you will eventually arrive at the point where you won't have to tell anyone about your opinion on a matter, instead you will be asked about it. (note: i have not arrived at that point yet, but i have seen the transition for others....)