This paper examines the concept of social persuasion, drawing primarily on Kaptein's (2012) definition and the foundational work of French and Raven (1959). It outlines six bases of social power — reward, coercive power, reference, legitimacy, expertise, and informational influence — and explores how each determines the degree of influence one individual can exert over another. The paper then evaluates several operationalization methods used to measure social persuasion as a psychological construct, including IRT rating scales, single-item measures, semantic differential scales, and even- and odd-numbered Likert scales. Each method is assessed for its strengths, weaknesses, validity, and reliability. The paper concludes by proposing an odd-numbered Likert scale model validated through a four-stage criterion process.
The paper exemplifies comparative instrument critique — a technique common in psychology and social science research methods writing. Rather than endorsing a single measurement tool, the author surveys multiple operationalization strategies (IRT, single-item, semantic differential, even- and odd-numbered Likert scales), evaluating each against consistent standards of validity, reliability, and practical utility. This approach signals methodological literacy and is especially effective in papers that culminate in a proposed research design.
The paper is organized in two main phases. The first phase (roughly half the paper) establishes the theoretical context: defining social persuasion and detailing the six bases of social power. The second phase shifts to methodology, reviewing and critiquing four types of measurement instruments. The paper closes with a brief proposal for the author's own preferred instrument and validation process, connecting theory back to measurement practice.
The term social persuasion has been defined differently by various researchers and scholars across different fields of study. For the purposes of this paper, however, Kaptein's (2012) definition and scope will be adopted. Social persuasion is thus defined as the symbolic ability "to convince other people to change their attitudes or behaviors regarding an issue, through the transmission of a message in an atmosphere of free choice" (Kaptein, 2012, p. 1). In other words, it is the art of getting a target to change their attitude or opinion about something and to consequently adopt a different viewpoint.
This conceptualization draws from the early works of Cartwright (1959) and Kurt Lewin (1951), both of whom held the view that an individual's behavior and attitude is the product of a range of forces or tensions within their life space, and their ability or inability to resist those forces. Towards this end, an individual's (call him individual A) ability to influence the attitudes or beliefs of another individual (B) is dependent upon the amount of influence A has over B, and the amount of resistance B puts up against that influence (French & Raven, 1959). Mathematically, this relationship could be represented as:
Effective persuasion = f (influence A, B, resistance B)
Unlike Lewin, Cartwright goes further to identify six factors that determine the amount of influence A would have over B. These six include A's information or knowledge base, as well as their expertise, legitimacy, reference, coercive power, and reward (French & Raven, 1959). Each is reviewed below as a distinct basis of social persuasion.
Reward: The amount of influence A has over B is dependent upon A's ability to decrease negative outcomes and mediate positive outcomes for B (French & Raven, 1959). Therefore, the higher B's expectation that A will actually do this, the greater A's influence. Moreover, the larger the expected outcome, the higher the degree of A's influence. As French and Raven (1959) note, contemporary scholars have added another dimension to this perspective — the success or failure of any persuasion process will also depend upon B's willingness to comply, and to allow A to maintain surveillance over them.
Coercive Power: This base rests upon the concept of punishment — that A would exert greater control and influence over B if B believes that A would punish them for non-compliance (French & Raven, 1959). In this case, the degree of influence depends primarily on the intensity of the punishment in question.
Reference: This element is based upon the degree of perceived similarity between the influencer and the subject, and the extent to which the subject desires to maintain that similarity (French & Raven, 1959). According to Schwenk (2009), one is likely to be more receptive to influence if they perceive themselves as significantly similar to the influencer. This is grounded in the assumption that people who belong to the same category understand each other's perspectives, interests, and attitudes more readily.
Legitimacy: This base draws upon the subject's internalized values, which grant the influencer the right to influence the subject's attitudes and impose upon the subject a sense of duty to comply (French & Raven, 1959). The degree of influence is highly dependent upon the source of the subject's values. If the influencer's legitimate power is derived from the subject's general values, it can be expected to extend across many different situations; however, if it is based on limited role characteristics, it is unlikely to affect situations outside the current one.
Expertise: This element is based on the extent to which the subject perceives the influencer as having superior knowledge or skills in a given area (French & Raven, 1959). The degree of influence the persuader holds over the subject depends upon their perceived level of knowledge and skills, and how relevant those attributes are to the situation at hand.
Informational Influence: This base equates an agent's degree of influence to the subject's perception of the significance and logic of the influencer's viewpoint. A person is likely to be more receptive to influence if they perceive the information provided by the influencing agent as significant, reasonable, and logical (French & Raven, 1959).
A great deal of research has been conducted on Cartwright's bases of social power, but as French and Raven (1959) point out, substantial knowledge gaps remain regarding the operationalization of these bases. All the same, there is consensus that persuasion plays an immeasurable role in almost all aspects of social interaction — marketers use it to drive sales, healthcare professionals use it to encourage healthy lifestyles, and psychologists use it to help clients change their evaluations of issues, objects, places, or other people. Persuasion is central to any profession that relies on others to achieve outcomes, and an influencing agent who is unable to convince others to act will face substantial professional challenges in their practice.
Several instruments have been developed to measure social persuasion as a psychological construct. The following sections review the most prominent methods, evaluating each for its validity, reliability, and practical utility.
One popular method of measuring social persuasion as a psychological attribute involves specifying and observing items of interest as functions of the construct under investigation. Schwenk (2009) employed this rating method in a study seeking to assess the relative significance of three bases — perceived similarity, coercive power, and authority — in the persuasion process. The overall purpose was to identify the strategy that yielded the best outcome. Three scales were developed for the three indices, with agreement ranging from 0 to 4 (4 representing "I agree" and 0 representing "I do not agree"). The influencing agent was presented as either similar or dissimilar to the target, or as experienced or inexperienced, and participants were required to rate the agent based on statements such as: "this agent has similar habits to me," "this agent has invaluable experience," and "this agent is appreciative of differences in opinion."
Despite the researcher taking several fundamental steps to ensure instrument validity, the results still indicated a misfit between the measuring instrument and the models used for the coercion and authority scales. The instrument, however, demonstrated high internal validity, with a Cronbach's alpha value of 0.05 for all three scales. To optimize reliability, the researchers maintained a constant ordinal structure for the items being measured. The coercion scale nonetheless yielded a lower level of reliability, as it was found to be highly sensitive to change.
One of the greatest strengths of the IRT method is its ability to create a flexible yet rigorous framework that allows for the placement of multiple items on a single scale, thereby promoting consistency across different assessment forms. Moreover, it can specify reliability for each individual item — in this case, perceived similarity, authority, and coercive power. However, to yield valid and reliable outcomes, the method must be used with large samples of data.
This study will adopt an odd-numbered Likert scale model, but differently from existing studies which base validity and reliability on external consistency. The proposed model will ensure all-round validity and reliability through a four-stage criterion, which involves: (i) generating a large pool of testable statements to reflect different characteristics of the construct under investigation; (ii) having judges rate the test items to identify those that clearly depict specific power bases; (iii) generating and judging influence situations in the development of scale standards; and (iv) analyzing all test items to determine those most relevant to the final scale.
Bearden, W., Hardesty, D. M., & Rose, R. L. (2001). Consumer self-confidence: Refinements in conceptualization and measurement. Journal of Consumer Research, 28(1), 121–134.
French, J. P., & Raven, B. (1959). The basis of social power. In D. Cartwright (Ed.), Studies in social power. Institute for Social Research.
Fuchs, C. (2009). Using single-item measures for construct measurement in management research. DBW, 69(2), 195–210.
Kaptein, M. C. (2012). Personalized persuasion in ambient intelligence. Eindhoven University of Technology Library.
Liu, O. L., & Wilson, M. (2010). Sources of self-efficacy belief: Development and validation of two scales. Journal of Applied Measurement, 11(1), 24–37.
Schwenk, G. (2009). Evaluating social influence relations: An item-response modeling approach. Metodoloski Zvezki, 6(1), 27–50.
Swasy, J. L. (1979). Measuring the bases of social power. In W. L. Wilkie (Ed.), Advances in Consumer Research (Vol. 6, pp. 340–346). Association for Consumer Research.
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