Is it better to go first in a debate, or second? Who has the advantage in court, the prosecutor who speaks first and can set the stage, or the defense attorney who has the final word? Do first impressions really matter? These questions and others like them have been the focus of a great deal of social psychological study since the mid-twentieth century.
Understanding when there is an advantage to going first or last could be a powerful communications tool. Not surprisingly then, determining whether or not people will attend to, remember, and be swayed by the first information they encounter (i.e., showing a primacy effect) or whether they will process, recall, and be convinced by the last information they encounter (i.e., demonstrating a recency effect) has been a major focus of research in the social psychological literature.
One of the more comprehensive approaches to the issue of primacy and recency effects has been in the persuasion literature. After World War II (1939-1945), the psychologist Carl Hovland (1912-1961) and his colleagues at Yale began to conduct research in order to understand how one could change people’s attitudes, and what contextual factors might influence the persuasive impact of a message. In their 1957 book The Order of Presentation in Persuasion, Hovland and his colleagues began to explore the issue of order effects. Many studies found primacy effects such that postmessage attitudes were more influenced by the first speaker or set of arguments. However, other studies found a recency effect, such that the perceivers were more influenced by the last information they encountered. Additional studies demonstrated neither primacy nor recency effects.
In 1959 members of the Yale group hypothesized that persuasion effects should work much like memory. If two messages were presented sequentially and without delay, the first message would be more persuasive because it would interfere with the processing of the second message (resulting in primacy effects). However, if the second message was presented after a sufficient delay (e.g., one week), the first message would have decayed and the second (or more recent) message would be stronger in memory, resulting in greater persuasion. Although some data supported this hypothesis, the findings were not straightforward. Interestingly, memory in and of itself was not a strong predictor of persuasion. Other research has explored how the familiarity of the issue or the types of information may influence the occurrence of primacy and recency effects.
More recent research has suggested that contextual factors, such as people’s ability and motivation to process the persuasive communication, are important determinants in whether primacy or recency will occur. Duane Wegener and his colleagues have presented evidence that when people are motivated and able to process information, they will demonstrate primacy effects. However, when motivation or ability are low, recency effects will tend to occur.
Perhaps not surprisingly, given the extensive work linking persuasion and memory, a number of researchers have explored how primacy and recency effects are manifested in human and animal learning and memory. Much of the research in this area is consistent with the findings in the persuasion literature. For example, contextual factors (e.g., type or topic of information, personal responsibility for outcomes, an individual’s motivation to think about the topic) have been found to moderate primacy and recency effects in human memory. Reviews of the primacy/recency literature have highlighted that both primacy and recency effects are possible depending on the context in which the information is learned.
There has also been substantial research on primacy effects in the field of impression formation (the study of how we make judgments about the people we meet). Consistent with persuasion and memory research, Phillip Tetlock and his colleagues have found that as one’s motivation to be a complete information processor increases (e.g., one has personal responsibility for the decision, the outcome is perceived to be important), there is a tendency for primacy and recency effects to diminish. As motivation decreases (personal responsibility is low, people are tired), biases can occur.
Thus, the question remains: Is it better to speak first or second if you want to convince your audience? Of course, as with most psychological questions, the right answer is "it depends." Most importantly, it depends on the knowledge, ability, and motivations of the audience. The impact of this research has been felt in many domains, including communications, marketing, and political science, among others. Indeed, as long as there is the possibility of gaining an advantage in the area of communications, it will be useful to conduct research to explore how and when order effects will occur.