Mood and persuasion

We live in a world of persuasion.  Advertisements try to convince us to buy products.  Stories on television and radio attempt to influence our opinion on a variety of topics.  Politicians seek to influence our beliefs about laws and society. 

When faced with an attempt at persuasion, we generally expect that stronger arguments for a position should have a bigger influence on our attitudes than weaker arguments.  Yet, when we look around the world, we see all kinds of strategies to persuade.  Many advertisements, for example, use celebrities to endorse the products.  It is a rather weak argument that we should eat a particular food or wear a specific watch just because a celebrity has been paid to appear in an ad, yet advertisers continue to use celebrities, which suggests that these ads must work (at least to some degree). 

Under some circumstances, almost any argument seems to be effective.  In a classic experiment by Ellen Langer, Arthur Blank and Benzion Chanowitz published in the Journal of Personality and Social Psychology in 1978, participants were 50% more likely to let someone cut in line to use a copy machine to make a few copies if they said, “May I use the Xerox machine, because I have to make copies”” than if they just said “May I use the Xerox machine?”  This additional information is a weak argument in favor of letting someone cut in, but any reason seemed good enough.  

An interesting paper in the April, 2013 issue of Personality and Social Psychology Bulletin by Rene Ziegler explored an additional wrinkle on attitudes by examining the influence of moods on the evaluation of attitudes. 

There are many potential influences of attitudes on mood.  On the one hand, research by Alice Isen and her colleagues suggested that positive moods tend to lead to more careful and creative thinking than negative moods.  On the other hand, negative moods can influence people to be more vigilant, which may make people in negative moods more critical of arguments.

Ziegler’s research suggests that people pay the most attention to arguments that oppose the mood they are in.  In the studies in this paper, participants evaluated arguments about topics that were not particularly important to them (like whether a shopping mall should be build in a nearby city).

In one study, participants first expressed their attitude about a number of topics including whether a mall should be built.  Then, people’s mood was manipulated by having them write about a past life event that was either happy or sad.  This kind of manipulation has been used in many previous studies to influence people’s mood. 

Next, participants read an argument about whether the mall should be built.  Some people read an argument in favor of building the mall, while others read an argument opposed to it.  The argument was designed to be either strong (focusing on things like the economic impact of the mall) or weak (focusing on the aesthetic design of the mall).  After reading the argument, participants rated their attitude about building the mall.

When an argument is consistent with people’s prior beliefs, then it is also consistent with their current mood, because we generally feel good when we read about things that we agree with.  When the argument is contrary to people’s beliefs, then it is inconsistent with their current mood, because we generally feel negatively when confronting beliefs we disagree with.

Participants in this study who already thought the mall was a good idea evaluated the argument more carefully when it opposed their prior belief than when it was consistent with that belief.  The measure of care was the difference in attitude following the strong or the weak argument.  That is, participants in a positive mood felt equally strongly about the mall after reading an argument that was consistent with their prior belief regardless of whether the argument was strong or weak.  But, participants in a positive mood who read an argument inconsistent with their prior belief felt more strongly about it when the argument was strong than when it was weak.  That is, people in a positive mood saw the difference between the strong and the weak argument when that argument was inconsistent with their initial belief.

The opposite pattern was observed for people in a negative mood.  For them, they responded to the strong and weak arguments differently only when those arguments were consistent with their previous belief. 

A second study in this series actually manipulated people’s initial belief about the domain and observed a similar pattern.

This research suggests that there is a complicated relationship between mood and persuasion.  We are driven to pay attention to information that is inconsistent with our current mood.  In a positive mood, we pay careful attention to arguments that disagree with our beliefs.  In a negative mood, we pay careful attention to arguments that agree with our beliefs.