How the Primary Effect Works

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Have you ever been asked to memorize a list of items? Or just been given a list of items that you tried to remember? If so, you might have noticed that it's easier to remember the very first items and the very last items on the list, but the ones in the middle are a bit hazy. This is due to something researchers refer to as the "primacy effect."

What is the primacy effect?
 Verywell / Jessica Olah

What Is the Primacy Effect?

In simplest terms, the primacy effect refers to the tendency to recall information presented at the start of a list better than information at the middle or end.

This is a cognitive bias that is believed to relate to the tendency to rehearse and relate memory storage systems.

Primacy vs. Recency Effect

In contrast to the primacy effect, the recency effect refers to the tendency for people to more easily recall items that are presented last in a list. In the case of the recency effect, this is likely due to those items being the most recent and therefore still being held in your short-term memory.

When you consider the primacy and recency effect in tandem, what you see is a u-shaped curve, also known as the serial position curve, for the recall of items on a list.

Causes of the Primacy Effect

What are the precise causes of the primacy effect? There are several causes that relate to how well information is attended to, practiced, and then later stored.


The main cause is likely the fact that people tend to rehearse items in order to remember them. This means that items presented early in the list are more likely to be remembered because they have been practiced more than items in the middle or at the end of a list. This is supported by evidence showing that when study participants are instructed not to rehearse or are not given enough time to rehearse, the primacy effect disappears.

Attention Span

There's also a second reason related to attention span. People are more likely to pay attention at the beginning and at the end of the presentation of a list of items, and so those are more likely to be remembered.

Think back to the last conversation you had, the paragraph you read, show you watched, or podcast you listened to. Chances are you may have zoned out at some points during the middle but probably were paying attention at both the beginning and the end.

Memory Limitations

Finally, the primacy effect likely persists because of limits in memory. A person might be able to store those first few items to long-term memory, and those last few items might reside in short-term memory, but the ones in the middle never get stored.

Early Studies on the Primacy Effect

Much research has focused on examining the primacy effect, going all the way back to the 1940s. In the typical study, participants are presented with a list of words, each shown for a fixed amount of time. After the words are presented, the participants are asked to write down all of the words from the list that they can remember.

Asch (1946)

Solomon Asch first examined the primacy effect in a study using sentences with reversed order of adjectives. In the study using two groups, a character was described as either "envious, stubborn, critical, impulsive, industrious, and intelligent" or "intelligent, industrious, impulsive, critical, stubborn, and envious." The results showed that the second description led to the person being rated more highly.

Murdoch (1962)

In a 1962 study conducted by Murdoch, participants were asked to learn a list of words that varied in length from 10 to 40 words. Each word was presented with a one or two-second gap in between. Using free recall, they were then asked to remember the words.

This study showed that the probability of recalling words on the list depended on their position on the list. Specifically, those at the beginning and the end were remembered more often.

Glanzer and Cunitz (1966)

In 1966, Glanzer and Cunitz gave two groups of participants the same list of words. One group was asked to immediately recall the words after being presented the list, while the other was asked to count backward in threes for 30 seconds before they had to recall the list.

The study results showed that preventing rehearsal in this way meant that both the primacy and recency effects disappeared.

What Influences the Primacy Effect

We know that the primacy effect is influenced by several factors based on the results of existing research. Let's have a look at what these factors are:

  • Time of presentation: The longer the time between the presentation of items on the list, the greater the primacy effect. This is due to people having time to rehearse.
  • Time of recall: When there is a delay in recall, it affects the primacy effect in a negative way such that it is reduced.

Memory and the Primacy Effect

Researchers have concluded that the primacy effect supports the idea of two separate memory systems at work: short-term memory (recency effect) and long-term memory (primacy effect).

  • The primacy effect involves rehearsing items until they enter long-term memory.
  • The recency effect involves the brain's ability to hold up to seven items in short-term memory.

This highlights that people are drawing on two different types of memory when they demonstrate the primacy and recency effect.

Impact of the Primacy Effect

How can you put this information about the primacy effect to use in your own life? Understanding the impact that the primacy effect might have on your decisions might help you make better judgments about a wide range of things.

Decision Making for Complex Choices

One important takeaway is that the way in which we receive information is a critical factor during complex decision-making processes. This might come into play when making a large purchase or an important decision in our lives.

Marketing experts are aware of this cognitive bias and use it to their advantage. They want your first impression and the last impression of a product to be positive. This is why you will see advertising for a product that is not yet available. It is also why a company will add extra finishing touches such as special packaging for a product. They want your first impression and last impression to be positive because these are the things that will matter.

It's important to be aware of this if you are making a complex decision. Instead of being led by marketing, do your own research and keep it in the forefront as you weigh your options. This will make it less likely that you will fall prey to advertising and marketing strategies.

Anchoring Effects

The primacy effect also has an important influence on a type of cognitive bias known as the anchoring bias. This bias involves relying too heavily on the first piece of information you receive (the "anchor") and neglecting any subsequent information you learn. The bias can have a wide range of effects on decision-making including how much you are willing to pay for something.

Research has also shown that it can have an effect on how doctors diagnose and treat illnesses accurately. The initial assessment a physician makes about a patient's health or illness creates an impression that then influences the assessment the doctor makes in the future.

Making a Lasting Impression

If there is something that you want to stand out: say it first, say it last, or both! This is when it is most likely to be remembered. If you're trying to convince someone of something, repeat your message several times so that it is remembered. Remember that serial position matters as well as the content of your message (positive vs. negative), so it's important to put this knowledge to use.

Learning and Studying

If you are a student, you can also put this information to use in your learning strategies. Become aware of your tendency to remember things from the beginning and end of what you study, and change up the position so that you can eventually store everything to your long-term memory.

Try focusing on particularly difficult concepts at the beginning of your study sessions and conclude each session with another quick review of that information.

A Word From Verywell

As if you already didn't have enough to remember, now you've got to remember what you might forget to remember! In its simplest terms, the primacy effect refers to our tendency to remember the first things we hear in a series. This makes logical sense, but it's not something you'd typically think about.

So the next time you find yourself in a high-pressure sales situation, trying to make a positive impression, or cramming for an exam, put this information to use.

Gather your research so you won't be unduly influenced, say what you want people to remember most first, and change up the order in which you study things so that you're more likely to remember everything.

What do you remember most from this article? Step away for a moment and try to list the main points you remember. Then check if you have also become an example of the primacy effect in action in your own life.

1 Source
Verywell Mind uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Saposnik G, Redelmeier D, Ruff CC, Tobler PN. Cognitive biases associated with medical decisions: A systematic reviewBMC Med Inform Decis Mak. 2016;16(1):138. doi:10.1186/s12911-016-0377-1

Additional Reading

By Arlin Cuncic, MA
Arlin Cuncic, MA, is the author of "Therapy in Focus: What to Expect from CBT for Social Anxiety Disorder" and "7 Weeks to Reduce Anxiety." She has a Master's degree in psychology.