Interviewers seem to use themselves / their same-race network as a reference point when judging skin tone. http://link.springer.com/article/10.1007/s12552-014-9128-z …pic.twitter.com/2NUZ6yCHQz
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Effect fairly small, 1 point on 10 point scale. Almost no effect on dispersion. Easy to adjust for. @KirkegaardEmil