I'd be interested to know the "curve" drawn when physical attractiveness is plotted against level of bias - whether there is a linear relationship, or whether the effect (indeed affect) tails off (or even turns negative?!) at some point. i.e. whether things just keep getting "better" the more attractive you are.
I think that the quoted Cialdini text blurs the distinction between physical attractiveness and grooming.
I can well imagine that people react positively to a well-groomed person because of the values such care over appearance indirectly demonstrates (social intelligence/wealth/hygeine etc.).
A halo effect based on pure physical attractiveness probably has more to do with a net positive bias resulting from a complex set of sexual dynamics created by different combinations of male/female and attractive/unattractive.
The affect heuristic is how an overall feeling of goodness or badness contributes to many other judgments, whether it’s logical or not, whether you’re aware of it or not. Subjects told about the benefits of nuclear power are likely to rate it as having fewer risks; stock analysts rating unfamiliar stocks judge them as generally good or generally bad—low risk and high returns, or high risk and low returns—in defiance of ordinary economic theory, which says that risk and return should correlate positively.
The halo effect is the manifestation of the affect heuristic in social psychology. Robert Cialdini summarizes:1
The influence of attractiveness on ratings of intelligence, honesty, or kindness is a clear example of bias—especially when you judge these other qualities based on fixed text—because we wouldn’t expect judgments of honesty and attractiveness to conflate for any legitimate reason. On the other hand, how much of my perceived intelligence is due to my honesty? How much of my perceived honesty is due to my intelligence? Finding the truth, and saying the truth, are not as widely separated in nature as looking pretty and looking smart . . .
But these studies on the halo effect of attractiveness should make us suspicious that there may be a similar halo effect for kindness, or intelligence. Let’s say that you know someone who not only seems very intelligent, but also honest, altruistic, kindly, and serene. You should be suspicious that some of these perceived characteristics are influencing your perception of the others. Maybe the person is genuinely intelligent, honest, and altruistic, but not all that kindly or serene. You should be suspicious if the people you know seem to separate too cleanly into devils and angels.
And—I know you don’t think you have to do it, but maybe you should—be just a little more skeptical of the more attractive political candidates.
1Robert B. Cialdini, Influence: Science and Practice (Boston: Allyn & Bacon, 2001).