Experimenting with
the halo effect
Nisbett and Wilson (1977) aimed
to try and discover how aware
people were of the halo effect. For
something that is such a key influence in how we judge people and
make inferences, surely we would
have an inkling of the process?
Nisbett and Wilson didn’t think so,
and designed a clever experiment
to test out their hypothesis. College
students were asked to evaluate
a psychology professor as they
watched a videotape of him being
interviewed. The students were
divided into two groups, with each
group shown a different interview
of the same instructor. The professor was a French speaking Belgian
who spoke English with a noticeable
accent. In one tape he appeared as
almost the perfect professor - kind,
respectful and likeable. However,
in the other he came across as a
cold and distrustful person with a
rigid teaching style. After the video
students in both groups were asked
to evaluate the professor based on
physical appearance, mannerisms
Thorndike was
the first researcher to support the
halo effect with
any empirical evidence. In his article ‘The Constant
Error in Psychological Ratings’ in
1920 he created the name the halo
effect, due to noticing in a past
study that estimates of character
traits in a person were very positive and highly correlated. Was it
possible that this person could
have so many good characteristics
across the board? In hope of finding a cognitive bias Thorndike carried out his own experiment. He
asked two commanding officers to
evaluate their men in physicality,
leadership, personal qualities and
intelligence. Thorndike wanted to
see if the rating of one characteristic corresponded to another. In fact
there was a huge correlation, with
soldiers rated all highly or almost
all negatively in all categories.
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