Serial Position Effect: What Is This Psychological Phenomenon?
People tend to remember the first and last items in a list better when they ask us to read it or listen to it to say it later.
This phenomenon is known as the serial position effect and is related to the way we encode and store our memories in short- and long-term memory.
In this article we explain what the serial position effect consists of, what the primacy effect and the recency effect are, and what the theoretical model on which it is based is.
The serial position effect occurs when we try to remember the items in a list and the items at the beginning and the end are remembered better than the items in the middle. This phenomenon was originally studied by Hermann Ebbinghaus, a German psychologist and pioneer of the use of the experimental method to study the functioning of human memory.
The tendency to remember the first items in a list better is called the primacy effect, and the greater probability of remembering the last items, recency effect. If this probability is graphed, a U-shaped curve is obtained that represents the precision with which memories vary depending on the position of the elements in a list.
This phenomenon is based on an experiment in which first, a subject is read a list with a certain number of items (unrelated to each other and greater than seven) and they are asked to listen to it carefully; and second, they are asked to write down the list items they remember in any order (free recall). The result usually corroborates the serial position effect, as well as the primacy and recency effects that we explain below.
When the elements are visual stimuli, those presented at the beginning exert a greater influence; Not only are they better remembered, but they also interfere with the memory of subsequent items. In the case of auditory stimuli, it is the elements at the end that exert the greatest influence; However, if several presentations of information are made separated in time and the subject must make a decision shortly after the last presentation, the recency effect usually has more influence on the decision.
The serial position effect also generates a general selection preference known as the order effect: we are more likely to select the first and last items in a list than the items in the middle (for example, as occurs with the order of candidates in a vote).
The primacy effect
The primacy effect, as we have commented previously, occurs when we are presented with a list with several items and then, When listing elements, we better remember those at the beginning This phenomenon occurs because the initial items are stored better in our long-term memory (LTM) than the last items. In fact, in lists in which items are presented quickly, the primacy effect is weaker, since we have less time to store them in the MLP.
The evidence that information that appears first is more likely to be remembered later can also be explained by the fact that there is more time for those first items to be repeated more times than the others, and therefore, they are more likely to be remembered. There is a transfer of information from short-term memory to the LTM.
The primacy effect also affects us when judging people In studies carried out by psychologist Solomon Asch, a list of words was listed in a different order with the aim of describing the character of another person. When positive adjectives were placed at the beginning (e.g., “intelligent, hard-working, selfish, and stubborn”), participants tended to judge the other person positively.
However, the phenomenon of primacy about how we judge other people and how they generate first impressions can also be related to attentional capacity and the fact that when we meet someone for the first time we tend to be on alert, and the first memory It always tends to have a more intense affective tone, which facilitates its long-term consolidation (we tend to remember better the experiences that have a greater emotional charge).
The recency effect occurs when we remember the last items in a list best This occurs because when we are asked to recall that list, the last items still remain in our working memory and, therefore, are more available and we can access them more quickly.
This phenomenon is not affected by the rate of presentation of the elements, but is affected by the passage of time and the exposure of additional information. For example, the recency effect disappears when the subject is forced to think about something else 30 seconds after the last item on the list is presented. This is something that does not happen with the primacy effect, since in that case the information has already been stored in long-term memory, something that does not happen with the phenomenon of recency.
The temporal context in which stimuli or list items are presented could also be related to the appearance of the recency effect. Such context could serve as a cue for the subject to retrieve stored information, a fact that would explain why more recent items that were processed in a different temporal context (earlier in the list) are more likely to be remembered.
On the other hand, this effect disappears or is substantially reduced when an interference task is introduced, in which working memory intervenes. Therefore, distracting stimuli (if they exceed 15 to 30 seconds in duration) can completely nullify this effect. Furthermore, if recall occurs immediately after the last item is presented, the phenomenon of recency is constant, regardless of how long the list is or the rate of item presentation.
Both the recency and primacy effects have been tried to be interpreted based on Atkinson and Shiffrin’s multi-store memory model This theoretical model postulates that these types of effects reflect the operations of two independent memory systems, including short-term memory (or working memory) and long-term memory, as well as another sensory memory store.
The short-term memory store lasts less than 30 seconds, unless the information contained is attended to and reprocessed (e.g. through repetition). George A. Miller studied this type of memory concluding that in that period of time we can learn seven pieces of information (give or take two). However, this data has been questioned and it is believed that it may vary depending on conditions.
Regarding long-term memory, the Atkinson and Shiffrin model postulates that it is a store to which information coming from short-term memory is transferred, as long as it is processed quickly enough. According to the authors, this warehouse would have a limited capacity and could last a lifetime. This would mean that we keep the ability to store new information relatively intact.
Finally, in relation to sensory memory, the model indicates that this store is responsible for retaining information that does not filter our attention and is not processed correctly. There are two types: the iconic or visual, which lasts approximately 500 milliseconds; and the echoic or auditory, with a duration of between three and four seconds.
However, although Atkinson and Shiffrin’s memory model remains useful in explaining certain phenomena, such as the serial position effect, Currently, other theoretical models are also used that complement and expand the multi-warehouse model such as processing models or connectionist models.
