The Mere Exposure Effect

“The brain tags familiar things as good things. Zajonc called this the ‘mere exposure effect,’ and it is a basic principle in advertising.” (Haidt, p. 65)

Something I need to understand better. When does it work and when does it not?


Philosophers and Moral Reasoning

Jonathan Haidt refers back to famous philosophers at a number of points in his book to show the evolution of ideas.

  • Plato believed that moral intuition was subordinate to reason.
  • David Hume believed that reason was subordinate to moral intuition.
  • Thomas Jefferson believed that moral intuition and reason were co-leaders.


Haidt’s position is that Hume was right.

The Rational Mind and Decision Making

Another way Haidt points out that we know morality is not necessarily a rational process is from his own experiments where people were given scenarios that trigger taboos but in which no one is hurt and no one outside of the main protagonists in the stories even know what happened.

Subjects were asked if the individuals in the stories were wrong to do what they did, and then pressed for reasons why. It was clear that most people were inventing reasons to justify their reactions. Even if they couldn’t give a good reason, they still stuck with their initial judgment.

It’s a pretty good demonstration that we’ve evolved to condemn certain behaviors, even if we can’t explain why, and even when those behaviors aren’t hurting anyone. Judgment and justification are separate processes.

Further, Haidt goes on to assert that moral reasoning is not about reconstructing our own conclusions, but rather “we reason to find the best possible reasons why somebody else ought to join us in our judgment.” (p. 52)

The Rational Mind and Social Decision Making

So, then, if our moral decision making is subconscious and automatic, why does our rational, conscious mind bother crafting post hoc justifications for what we believe? Haidt refers to our rational minds as a press secretary. Why bother with the post hoc reasoning, since we aren’t going to change anyone else’s mind?

Partly, it serves a social function. Reason itself isn’t very effective for changing minds, but it can reinforce our beliefs and the beliefs of other, like-minded individuals. It feels good when someone comes up with a killer argument in favor of what we believe, and that creates social bonds.

It’s also true that we do sometimes change our positions, particularly in response to people who we like or admire assuming a contrary position. Our rational brains help us rationalize the reasons why we change our views, when really we changed them due to social pressure.

Also, to be clear, it is also possible to change your own position based on logical reasoning, and we clearly sometimes do. As Haidt notes, it just doesn’t happen very often.

The Role of Cognitive Load in Decision Making

Haidt did some research early in his career to ascertain whether increased cognitive load would interfere with making decisions in situations that involve applying morality or ethics. The idea here is that if morality is controlled by automatic processes instead of rational ones, then cognitive load shouldn’t matter.

And, indeed, that’s what he found. Moral judgement is fast and automated. It doesn’t depend on the rational mind.

The Role of the Emotional Brain in Decision Making

Haidt, early in The Righteous Mind, shares the work of Antonio Damasio, a neuroscientist who noticed that people with a particular brain injury in the prefrontal cortex felt almost no emotions but retained complete ability to reason (no drop in IQ) and to discriminate between right and wrong. These individuals could reason just fine–but they couldn’t make decisions. And when they did, they were often poor ones. Their lives began falling apart.

Every single decision had to be based on rationally considering all the options. This is a nightmare for working memory, and I imagine exhausting, leading to poor decisions.

This is interesting evidence that our rational brains don’t have as much control as we think they do. We depend on emotions.

The Righteous Mind

I’m reading The Righteous Mind: Why Good People Are Divided by Politics and Religion by Jonathan Haidt. I loved, loved, loved his earlier book The Happiness Hypothesis, so I’m going to go off topic on this web journal for a while and instead use it as a place to think about Haidt’s ideas.

Haidt’s default political perspective, and he’s up front about this, is liberal atheist. One of the things I enjoy about him as an author is that he’s interested in the research base even when it doesn’t support his intuitions. He seeks disconfirming evidence!

It was interesting to read in his introduction that the word liberal has a different meaning here in the states than it does in Europe, where the meaning is closer to libertarian. Liberal here maps more cleanly to progressive in Europe.