8.9: Primacy and Recency Effects

The Primacy Effect

John is envious, stubborn, critical, impulsive, industrious, and intelligent. In general, how emotional do you think John is? (Pick one).

Not emotional 1 2 3 4 5 6 7 8 9 Extremely emotional

Some memory effects depend on time, on the temporal context. Particularly, early items in a list like this influence our impressions and inferences about someone much more strongly than later items do. This stronger influence of earlier items or situations is called the primacy effect. The primacy effect means that events or features appearing early in a series are easier to remember than later ones.

Other things being equal, first impressions (and to a lesser extent, second and third impressions) have a stronger impact on people than later impressions. There are many situations where this is relevant, including the first impression you make on a date or at a job interview. The first sentence, paragraph and page of a paper make a first impression on its readers, and if it is bad, they are likely to judge the whole paper as bad. The first quiz or exam you take in a course might also influence the professor’s evaluation of your work generally (which is why good teachers should grade blind).

One plausible explanation for the primacy effect is that we have a limited amount of time and attention, so we can’t constantly monitor everything and update our views. If this is correct, the effect may involve attention and perception as much as memory, but it shows up when we think back over the series of things. By giving more weight to early impressions than to later ones, we rely on a biased sample. This leads us to draw inferences based on inductively weak reasons. Such inferences are flawed. But if we are aware of this tendency, we can try to avoid it in ourselves. We can also try to create the best first impression that we can.

The Recency Effect

Although the first items in a series tend to be given more weight than later ones, items at or near the end of the series may also be given more weight than average. This seems intuitive: items near the end are fresher in our minds.

Which effect is stronger? There is some evidence that when presentations are involved, there can be a strong recency effect. But when we judge other people, the primacy effect is much stronger. But even this depends on the context. Early in a relationship, first impressions loom large, and initial attraction can overpower red flags. But after thirty years of marriage, the first impression won’t matter as much as later impressions.

In a detailed study, Miller and Campbell edited court transcripts in a case seeking damages due to a defective vaporizer. All the material supporting the plaintiff was placed together in one long block, and all the material supporting the other side was placed in another long block. The existence of primacy and recency effects depended on delays in the process.

1. If people heard each side’s case and then made a judgment about them, neither a primacy nor a recency effect was observed.
2. If people heard both messages back-to-back, then waited a week to make a judgment, there was a primacy effect (the view presented first did better).
3. If people heard one message, waited a week to hear the second, then immediately made a judgment, there was a recency effect (the view presented last did better).

What might explain this? When there was a week between presentations, people remembered much more about the side presented last. This seems to explain the recency effect in these conditions. What might explain the primacy effect where it occurs? The study suggests a bit of advice. Speak first if the other side will speak right afterwards and there is a delay in the response to the presentations. But speak last if there will be sometime between the two presentations and the response to the presentations will come right after the second.

One great thing about understanding primacy and recency effects is this is an area where obvious safeguards present themselves. The more information is presented in relatively brief chunks, the more beginning and ends there are for the primacy and recency effect to take hold. The middle is where more information is lost, so by minimizing the amount of middle, we minimize loss. This explains why the information in this text is presented in so many sections. You can use this to your benefit as well, by pausing between sections to reflect on the material before moving on to the next section. You have likely noticed that when you sit down and just read a chapter of any textbook in one sitting, very little of it manages to be encoded.