Found this question and answer searching "confirmation bias" and "accepted answer". I think the green check box might be too close to the up / down-vote controls. I don't question the existing up votes for questions, but I had observed that accepted answers tend to get the most votes -- which I'll admit makes a lot of sense for all the reasons cited in the answer to the linked question. A lot of factors can go into why someone will up-vote.
The only reason I raise this question is that I caught myself feeling an unbidden urge to up-vote the accepted answer on a question I had just up-voted, even though I hadn't really read the answer to see if it helped me in my particular situation or was particularly well written. I think, particularly for long time users of SE sites, the green check and reputation bumps begin to become Pavlovian stimuli, creating a positive feedback reward in our minds. We respond favorably to the shade of green, perhaps.
I'm not suggesting that we change any mechanics or stats, just that the placement of the green check be reconsidered.
Does it seem to you that the green check lends some authority to an answer beyond it's content sometimes?
What if the green check were moved to the right side of a question so that the effect of its proximity to the up/down arrows was limited?
Alternately, what if we changed the color of the check from green to brown, red, purple or some disassociated color? Would that create confusion or reduce the usability of the design or help dissipate confirmation bias?