What is the Primacy Effect?
You know the cautionary dating advice “first impressions matter”? Well it has a solid basis in cognitive psychology, at least if your date is a list of words.
The primacy effect is the tendency to remember the first piece of information we encounter better than information presented later on. You will have experienced this yourself anytime you have tried to learn a list of items. It’s much easier to recall the first item on the list than one in the middle.
Items that appear first on a list are stored in long-term memory more easily than subsequent items further down the list. It takes less processing power for the brain to rehearse and recall a single item (the first item on the list), than multiple items (the items later in the list in addition to the preceding ones). This is in evidence when people read a series of statements about a person, the amount of time they spend reading the items declines with each new piece of information (Belmore & Hubbard, 1987).
We are more likely to show the primacy effect when we are tired than when we are wide awake and when we are distracted than when we are paying attention (Webster, Richter, & Kruglanski, 1996).
The primacy effect is connected to the recency effect, the fact that we recall the latest information better. For example, in competitions such as the Eurovision Song Contest and ice skating, it has been found that higher marks were given to competitors who performed last De Bruin (2005) .
Why is it Important?
This effect needs to be taken into account anytime a series of people, objects, or ideas are presented to someone, to reduce the importance of the first ones compared to the others. Early traits lead us to form an initial expectancy about the people we meet, and once that expectancy is formed, we tend to process information in ways that keep that expectancy intact. Unfortunately, once we have developed a schema, it becomes difficult to change it.
There are important implications for teaching, as students are more likely to recall information presented earlier in the learning episode than in the middle, therefore it makes sense to front-load the most important aspects of a lesson.
Koppell and Steen (2004) found that in elections in New York City, the candidate who was listed first on the ballot was elected more than 70% of the time, and Miller and Krosnick (1998) found similar effects for candidate preferences in laboratory studies.
Asch (1946) presented study participants with lists of character traits. The lists contained exactly the same traits but in reverse order. He found that participants who read lists where positive traits came first formed more favourable impressions than those who read lists with negative traits first.
Companies often use television, radio, internet and print advertising to present you with a first impression of their product or service, even before it is available. This is seen in news stories about upcoming phone releases or movie previews. Therefore there is often an incentive to make sure the first news you hear about a product is positive.