Social judgments and impression formation  

Most of the early evidence suggesting a negativity bias stems from research on
social judgments and impression formation, in which it became clear that
negative information was typically more heavily weighted when participants
were tasked with forming comprehensive evaluations and impressions of other
target individuals.  [9]  [10]  Generally speaking, when people are presented
with a range of trait information about a target individual, the traits are
neither "averaged" nor "summed" to reach a final impression.  [11]  When these
traits differ in terms of their positivity and negativity, negative traits
disproportionately impact the final impression.  [12]  [13]  [14]  [15]  [16]
This is specifically in line with the notion of negativity dominance  [4]
(see "Explanations" above).

As an example, a famous study by  Leon Festinger  and colleagues investigated critical factors in predicting
friendship formation; the researchers concluded that whether or not people
became friends was most strongly predicted by their proximity to one another.
[17]  Ebbesen, Kjos, and Konecni, however, demonstrated that proximity itself
does not predict friendship formation; rather, proximity serves to amplify the
information that is relevant to the decision of either forming or not forming
a friendship.  [18]  Negative information is just as amplified as positive
information by proximity. As negative information tends to outweigh positive
information, proximity may predict a failure to form friendships even more so
than successful friendship formation.  [2]

One explanation that has been put forth as to why such a negativity bias is
demonstrated in social judgments is that people may generally consider
negative information to be more diagnostic of an individual's character than
positive information, that it is more useful than positive information in
forming an overall impression.  [19]  This is supported by indications of
higher confidence in the accuracy of one's formed impression when it was
formed more on the basis of negative traits than positive traits.  [2]  [14]
People consider negative information to be more important to impression
formation and, when it is available to them, they are subsequently more
confident.

An oft-cited paradox,  [20]  [21]  a dishonest person can sometimes act
honestly while still being considered to be predominantly dishonest; on the
other hand, an honest person who sometimes does dishonest things will likely
be reclassified as a dishonest person. It is expected that a dishonest person
will occasionally be honest, but this honesty will not counteract the prior
demonstrations of dishonesty. Honesty is considered more easily tarnished by
acts of dishonesty. Honesty itself would then be not diagnostic of an honest
nature, only the absence of dishonesty.

The presumption that negative information has greater diagnostic accuracy is
also evident in voting patterns. Voting behaviors have been shown to be more
affected or motivated by negative information than positive: people tend to be
more motivated to vote against a candidate because of negative information
than they are to vote for a candidate because of positive information.  [22]
[23]  As noted by researcher Jill Klein, "character weaknesses were more
important than strengths in determining...the ultimate vote".  [23]

This diagnostic preference for negative traits over positive traits is thought
to be a consequence of behavioral expectations: there is a general expectation
that, owing to social requirements and regulations, people will generally
behave positively and exhibit positive traits. Contrastingly, negative