This approach to persuasive communications was first studied by Carl Hovland and his colleagues at Yale University during World War II.
[2] This approach has helped social psychologists understand the process of persuasion and companies make their marketing and advertising strategies more effective.
The Yale researchers did not specify levels of importance among the factors of a persuasive message; they emphasized analyzing the aspects of attitude change over comparing them.
[7] They established the Yale Communication Research Program which aimed to understand and examine factors that influenced attitude change.
[3] The Yale group examined attitude change from a learning theory perspective and information processing approach.
[8] The Yale school's approach is considered convergent:[7] it started with identifying a phenomenon (attitude change) and then searched for an explanation by looking at variable factors and their effect on the phenomena.
[7] The Yale school also suggested that message processing take place in stages: attention, comprehension and acceptance.
[3] The Yale group had a total of five publications reporting the findings of their experiments (including Communication and Persuasion) that further explored each factor under the same model.
[3] An exception to the gradual dissociation of the effects of a persuasive message were reported in studies conducted by Hovland, Lumsdaine, and Shieffield.
[3] The Yale school focused on factors such as motivating appeals[3] and organization of arguments in regards to the content of the communication.
[3] Janis and Feshbach in 1953[13] explored degrees of intensities of fear appeal and their effects on conformity in the context of the consequences of poor dental hygiene.
Hovland, Lumsdaine, and Sheffield explored the effectiveness of one-sided and two-sided messages (containing pros and cons).
A 1953 follow up study conducted by Lumsdaine and Janis[14] explored the resistance of opinion change motivated by argument structure.
They brought forth emphasis on the importance of learning theories behind attitude change and laid a strong foundation of mass findings that stimulated further research related to persuasion.
[19] The study of persuasion has always been an integral part of social psychology with the focus slowly moving from attitude change and behavior modification to communications, literature, art and the other humanities.
The Yale group's original research "stemmed from a variety of theoretical approaches, including, among others, Hull's learning theory, some motivational hypotheses of Freud and other psychoanalysts, and some of the formulations of Lewin, Sherif, Newcomb, and others".
[7] McGuire emphasized the importance of reception (the attention and comprehension stages of the Yale group) and yielding (anticipation and critical-evaluation steps) in his study of individual differences in influenceability.
[24][25] McGuire is best known for his inoculation theory of exploring resistance to persuasion, which was influenced by the Yale school's research on the resilience of two-sided messages on opinion acceptance.
Developed by Petty and Cacioppo during the late 1980s, the model describes two ways in which persuasive communications can cause attitude change: centrally and peripherally.
The central route to persuasion occurs when people have the ability and motivation to listen to a message, think about its arguments and internalize the information.
Under the peripheral route, the recipient relies on the context of the situation rather than the information at hand (i.e. they look at attractiveness in this case or if the person speaking is famous or not).
Using the concept of the fait accompli (a completed, irreversible "done deal"), Bauer described artifacts such as nuclear power, information technology and genetic engineering as types of social influence.
Research on external factors which influence individual's attitude has a strong focus on marketing strategy applications.
[27] There is significant financial interest in examining the impact of source credibility, communicator attractiveness, message context, and mood on persuasion and attitude change.
Eagly and Chaiken surveyed undergraduate students on communicators' attractiveness and whether they were persuaded to adopt the speaker's position (desirable or undesirable) on a topic.
Hovland states[30] another set of factors that impact attitude change, specifically, in order for the communication to be accepted by the recipient.
Conversely, a study by Cantril and Allport (1935)[30] suggest that radio may be more effective than print because the individual identifies as part of a larger group of people listening to the same program at the same time.
Key to this theory is an "interactive society"[33] with technology allowing communities to share common values and beliefs, such as the Internet.
Another form of public persuasion, studied by Helene Joffe, explores how the media produces visual stimuli which elicit feelings of fear, empathy or disgust.
This theory highlights the substantial role of technology in evoking emotion in individuals, focusing on advertising campaigns for health, safety and charities.