The serial position effect refers to the finding that recall accuracy varies as a function of an item's position within a study list. When asked to recall a list of items in any order (free recall), people tend to begin recall with the end of the list, recalling those items best (the recency effect). Among earlier list items, the first few items are recalled more frequently than the middle items (the primacy effect). See and for details.
One suggested reason for the primacy effect is that the initial items presented are most effectively stored in long-term memory because of the greater amount of processing devoted to them. (The first list item can be rehearsed by itself; the second must be rehearsed along with the first, the third along with the first and second, and so on.) One suggested reason for the recency effect is that these items are still present in working memory when recall is solicited. Items that benefit from neither (the middle items) are recalled most poorly.
There is experimental support for these explanations. For example:
The primacy effect, in psychology and sociology, is a cognitive bias that results from disproportionate salience of initial stimuli or observations. If, for example, a subject reads a sufficiently long list of words, he or she is more likely to remember words read toward the beginning than words read in the middle.
The phenomenon is said to be due to the fact that the short term memory at the beginning of whatever sequence of events is being presented, is far less 'crowded' and that since there are far fewer items being processed in the brain at the time when presented than later, there is more time for rehearsal or pondering of the stimuli which can cause them to be 'transferred' to the long term memory for longer storage.
The recency effect is comparable to the primacy effect, but for final stimuli or observations. Taken together the primacy effect and the recency effect predict that, in a list of items, the ones most likely to be remembered are the items near the beginning and the end of the list (serial position effect). Lawyers scheduling the appearance of witnesses for court testimony, and managers scheduling a list of speakers at a conference, take advantage of these effects when they put speakers they wish to emphasize at the very beginning or the very end of a long list.
The inverse of this effect is the primacy effect. The recency effect is compatible with the peak-end rule.
Furthermore, the effect also refers to the effect in autobiographical memory that people recall more recent than remote personal events.
Another example of the recency effect is applied by lawyers. The key witnesses will go at the end of list (or the beginning to take advantage of the primacy effect), so the jury will keep them in mind while they deliberate.