Any time people are asked to review their peers, there's at least some compulsion to rate others poorly because it'll make you look better. IME, the only times

Any time people are asked to review their peers, there's at least some compulsion to rate others poorly because it'll make you look better. IME, the only times that it can go well is with people who don't think the results will matter. And in which case, why do it? The one exception is someone who is already somewhat of a leader and isn't looking for a promotion, and so they don't have much desire to make themselves look better.