Primacy bias is the tendency to more easily recall information that we encounter first. In other words, if we read a long list of items, we are more likely to remember the first few items than the items in the middle.

We also tend to assume that what is at the beginning of a list is of greater importance or significance. Due to this, primacy bias (or primacy effect) has far-reaching consequences in different contexts, such as job interviews, education, and advertising.

What is primacy bias?

Primacy bias is a type of cognitive bias or mental shortcut that helps us process information quickly but not always correctly. As a result, we can better recall the earliest information we encounter.

This is why being first at a job interview is advantageous: you are more memorable than candidates interviewed in the middle. Similarly, it’s easier to recall the beginning of a lecture or the first speaker at a conference.

Because of primacy bias, what comes first in a sequence of things or events is most noteworthy. This explains why first impressions carry more weight in our judgment when meeting a new person. If the first time we are introduced they happen to be rude or unpleasant, we form a negative impression of them. This impression is likely to stay even if there is evidence to the contrary later on.

What causes primacy bias?

There are several interrelated reasons that can help explain why primacy bias affects our ability to recall information, such as:

• Repetition. Items at the beginning of a list are encountered first, so we have more time to rehearse those items and memorize them. The more we rehearse information, the more likely it is to be eventually stored in our long-term memory, becoming easier to recall.
• Attention. Because our attention span is limited, we are more focused when we start reading something or at the beginning of a presentation. As we continue, our minds drift to what we previously heard or read or to something entirely different.
• Memory. Our capacity to remember things is also limited. To save energy and effort, our brains choose what to keep and what to forget. In general, it takes less effort to rehearse and recall a single item (the first item on the list) than several items (the items later in the list, in addition to the initial ones). Because of this, top-of-the-list items are more likely to pass our selection process and end up in our long-term memory than middle-list items.

What is the difference between primacy bias and recency bias?

Primacy bias and recency bias are both parts of what is called the serial position effect. According to this phenomenon, our ability to recall different items on a list or series depends on their position.

The difference is that primacy bias causes us to remember the first items in a series better than the ones that follow, while recency bias causes us to remember the last (or most recent) items better than preceding items.

Combining the primacy and recency bias, we can conclude that people tend to forget information from the middle of a list or series. In other words, when we have an important message to convey, it’s best to place it at either the beginning or the end.

Primacy bias example

Primacy bias has implications for elections because the top spot on the ballot provides an advantage to the candidate whose name occupies it.

Because job interviews are mostly conducted under time pressure, they are fertile ground for different types of bias, including primacy bias.