The biggest favor you can do for your students is to set a high standard up front and hold them to it. The sooner students learn that success comes from good performance, the better they will do not only in their academic careers, but all throughout life. If we, as teachers, do not hold our students to high standards, we are not doing them any favors, since their future employers will not be so understanding. It is a natural instinct to want to give the students who are good in section the benefit of the doubt when you grade their papers. Unfortunately, this violates the concept of fairness.
Some students are good at conveying concepts orally and are aggressive in section.
Then there are the quiet ones, or the ones who are distracted. In any case, a written assignment can only be graded on what the student writes. As hard as it is to do, when you sit down to grade, flip over the cover page without looking at the name. What needs to be assessed is the student's performance on the assignment, judged by the standards you have set and made known to the students, and nothing more. Of course section participation should count as well.