What is the serial position effect?

The serial position effect is the tendency to remember the first and last items in a list better than the items in the middle. Plotted as recall against position in the list, it makes a U-shaped curve. The advantage for the first items is called the primacy effect and the advantage for the last items is called the recency effect.

What is it called when you remember the first and last thing?

Remembering the first items best is the primacy effect; remembering the last items best is the recency effect. Together they make up the serial position effect.

What is the difference between the primacy effect and the recency effect?

They have different causes. The primacy effect comes mainly from extra rehearsal: the first items get repeated more often in your head and are more likely to reach long-term memory. The recency effect comes mainly from the last items still being held in short-term memory when you start recalling. That is why a short distracting task before recall removes the recency effect but leaves the primacy effect largely intact.

Who discovered the serial position effect?

Hermann Ebbinghaus first described the effect of list position in his memory experiments, published in 1885. The classic modern measurement is Bennet Murdock's 1962 study of free recall, and Murray Glanzer and Anita Cunitz showed in 1966 that the two ends of the curve respond to different manipulations.

How does the serial position effect affect everyday life?

It shows up wherever information arrives in a sequence: the first and last points of a talk, the first and last candidates in an interview day, the opening traits in a description of a person, and the order of performers in a contest. A study of 47 Eurovision Song Contests and several figure skating championships found that performers who appeared later tended to receive higher scores.

Is the serial position effect related to IQ?

Indirectly. People with higher working memory capacity tend to recall more from both ends of a list, and working memory capacity is related to fluid intelligence. But everyone shows the U-shaped curve; it is a feature of how human memory works, not a sign of high or low intelligence.

Serial Position Effect: Primacy & Recency

The serial position effect is the tendency to remember the first and last items in a list better than the items in the middle. The advantage for the opening items is the primacy effect; the advantage for the closing items is the recency effect. Plot recall against position and you get a U-shaped curve. Hermann Ebbinghaus first described it in 1885, and it remains one of the most reliable findings in memory research.

The serial position effect at a glance

Primacy effect: the first few items are recalled well, mainly because they get rehearsed more and reach long-term memory.
Recency effect: the last items are recalled well when you recall straight away, because they are still held in short-term or working memory.
The middle: items in the middle get neither advantage and are recalled worst.
Two causes, not one: a short delay wipes out recency but leaves primacy; slowing the list down boosts primacy but not recency.
Beyond lists: the same pattern shows up in first impressions, interviews, contests and presentations.

The classic experiment: Murdock’s U-shaped curve

In 1962 Bennet Murdock read people lists of common words, from 10 to 40 words long, and asked them to write down as many as they could in any order (a task called free recall). Whatever the list length, the curve had the same shape. In his description, a steep primacy effect covered roughly the first three or four words, a recency effect covered roughly the last eight, and in between recall sat on a flat, low plateau. Longer lists lowered the plateau, but the ends stayed strong.

Why the first and last items stick: two kinds of memory

The most influential explanation is that the two ends of the curve come from different memory stores. In 1966 Murray Glanzer and Anita Cunitz tested this with two manipulations:

Slower presentation (3, 6 or 9 seconds per word) improved recall of the early and middle words but barely changed the last few. More time per word means more rehearsal, which helps transfer into long-term memory.
A short delay filled with counting aloud, before recall, reduced recall of the last words, and a 30-second delay removed the recency effect entirely. The early words were largely unaffected.

Each manipulation moved one end of the curve and left the other alone, which is what you would expect if primacy reflects long-term storage and recency reflects a short-lived store. Dewey Rundus (1971) added direct evidence for the primacy side. He asked people to rehearse out loud while a list was being presented and found that the first items were repeated far more often than later ones, and that the more often an item was rehearsed, the more likely it was to be recalled.

Evidence from patients points the same way. In 1970 Alan Baddeley and Elizabeth Warrington compared people with amnesia, who have great difficulty forming new long-term memories, with control participants. The amnesic patients showed a normal recency effect in immediate recall but did much worse on the earlier part of the list, consistent with an intact short-term store and an impaired long-term one.

The complication: recency that lasts

The two-store story is not the whole picture. In 1974 Robert Bjork and William Whitten put a distracting task after every item in a list, not just at the end, so that nothing could sit in short-term memory. A recency effect still appeared. This “long-term recency” suggests that recent items also benefit from being more distinct in time: what matters is how far back an item is relative to the gaps between items, a little like telegraph poles, where the nearest ones stand out clearly and the far ones blur together. A common reading today is that short-term storage explains much of the ordinary recency effect in immediate recall, while temporal distinctiveness and retrieval cues account for recency that survives a delay.

Primacy and recency in everyday life

First impressions. In Solomon Asch’s 1946 experiments, people heard a person described as “intelligent, industrious, impulsive, critical, stubborn, envious” or the same six words in reverse order. The version that began with the positive traits produced a noticeably more favourable impression. This is primacy in judgement rather than in memory, and it overlaps with other cognitive biases.
Contests and juries. Wändi Bruine de Bruin analysed 47 Eurovision Song Contests (1957–2003) and European and World Figure Skating Championships (1994–2000). Scores tended to rise with performance order, even though judges rated each act soon after seeing it.
Interviews and talks. Points made at the start and end of a talk, or candidates seen first and last, are better remembered than those in the middle.
Shopping lists and phone numbers. If you forget something from a list, it is most likely to be from the middle.

How to use the serial position effect

Studying: change the order you review material in, so the same topics are not always stuck in the middle. Short sessions create more beginnings and ends.
Presenting: put your key point at the start and repeat it at the end.
Long lists: break them into short groups, as our page on chunking explains; each group gets its own first and last items.
Judging others: if you assess people or work in sequence, take notes on each one before moving on, so the order does not decide for you.

For memorising long ordered material, techniques such as the memory palace give every item its own location, which helps the middle of a list as much as its ends.

The serial position effect and IQ

Everyone shows the U-shaped curve, so it is not a measure of intelligence. What differs between people is how much they recall overall. In a 2007 review, Nash Unsworth and Randall Engle argued that individual differences in working memory capacity come partly from how well people keep information active (which supports the recency end in immediate free recall) and partly from how well they search long-term memory for the rest. Working memory capacity in turn is related to fluid intelligence, as our guide to fluid and crystallized intelligence describes. The link is a correlation across groups; your recall of a shopping list says little about your IQ.

Trust and scope notes

This page summarises published research for general information, with figures taken from the studies listed below. It is not medical advice: memory problems that are new, worsening or worrying deserve a conversation with a doctor, and no online test can assess them. The IQ Revealed test is an online reasoning test of 40 original items for adults aged 18 and over; it is not a clinical assessment and it does not measure memory for lists. Our guide to how IQ tests work explains what an online test can and cannot tell you.

IQ Revealed is not affiliated with, endorsed by or connected to the researchers, universities, journals, publishers, competitions or event organisers named on this page, including the Eurovision Song Contest. Names are used only to identify the research being described.

Serial Position Effect: Primacy, Recency and Why We Forget the Middle