Fishbein's Subjective Norm: Theoretical Considerations and Empirical Evidence

THE RELATIVE IMPORTANCE OF A_B AND SN

One finding of the studies dealing with Fishbein's behavioral intention model is that there has been a tendency for behavioral intention to be primarily determined by attitudinal factors (Fishbein, 1975, p. 311). There are two explanations for this finding. The first is that since the relative weights of the two components are expected to vary as a function of the topic and population under investigation, the slight tendency for attitudinal considerations to play a dominant role in determining intention is due to the fact that for the particular topics and populations studies, attitudinal considerations in fact were dominant. The second explanation is that the impact of normative beliefs in determining intention is felt in the attitudinal component. That is, one of the determinants of an individual's favorable attitude toward buying a particular product might be that he believes that Referent X will be pleased.

Another question pertaining to the relative importance of the normative and attitudinal component concerns the psychological meaningfulness of the weights. While the weights have been shown to vary across topics and populations, one might question whether these weights are meaningful or are merely "statistical artifacts." The results of studies pertaining to this question are inconclusive. Two of the studies (Ajzen and Fishbein, 1970 and Ajzen, 1971) used a Prisoner's Dilemma game. In both studies, some subjects were told to treat the other player as a partner (cooperative condition) while others were told to try to do better than the other person (competitive condition). It might be expected that in the cooperative condition normative factors would be dominant while in the competitive condition attitudinal factors would be dominant. As seen in Table 1, the results were encouraging.

TABLE 1

ATTITUDINAL AND NORMATIVE WEIGHTS IN PRISONER'S DILEMMA GAMES

Also of relevance is a study conducted by Glassman (1971). In this field study conducted among working class housewives, 127 respondents were asked questions pertaining to their beliefs, attitudes and intentions to buy eight convenience goods which had been selected because of their particular location on the Cohen and Barban (1970) product typology. Four of the products (two brands each of coffee and laundry detergent) were classified as ego-conspicuous products, i.e., they gave the consumer a sense of personal satisfaction (ego involved) and they were in some way visible to others (conspicuousness), while four of the products (two brands each of gasoline and potato chips) were classified physiological-inconspicuous, i.e., the products did nothing more for the consumer than the jobs for which they were designed (physiological) and the products and/or the results of their use were not visible to others (inconspicuousness). In addition, respondents completed the C.A.D. personality inventory (Cohen, 1967). This instrument classifies individuals according to their interpersonal orientation. Specifically, an individual can be viewed as moving toward people (compliant), against people (aggressive) or away from people (detached). Since perceived social conspicuousness has been called the most general attribute bearing on a product's susceptibility to reference group influence (Bourne, 1963), it was hypothesized that the intention to purchase those products that were classified as being ego-conspicuous would be primarily determined by normative factors while the intention to purchase those products that were classified as being physiological-inconspicuous would be primarily determined by attitudinal factors.

TABLE 2

REGRESSION COEFFICIENTS FOR EIGHT CONVENIENCE GOODS

It can be seen in Table 2 that irrespective of product classification, attitudinal considerations were the primary determinant of intentions. In fact, for three of the four ego-conspicuous products, the regression coefficient of the normative component was insignificant. However, it was encouraging to note that normative considerations played a significant role in deter- mining intention to purchase gasoline (physiological- inconspicuous). Specifically, subsequent analyses showed that the women felt that their husbands had very definite ideas as to which gasoline should be purchased and there was a strong motivation to comply with this referent. It was also felt that the extent to which a respondent was compliant, aggressive or detached, would influence the amount of importance that she placed on each of the components of the model. Specifically, it was hypothesized that for those women who classified themselves as being compliant, intention would be primarily a function of normative considerations while for those women who were aggressive or detached, attitudinal considerations would be primary. Since 70.6% of the women classified themselves as being primary compliant it was felt that a compliant versus aggressive and detached analysis would be inappropriate. Rather, the sample was divided into three groups on the basis of their compliance score. The results did not lend support for the hypothesis.

THE SUBJECTIVE NORM

SN:    Others who are important to me think I should +3:___:___:___:___:___:-3: I should not perform Behavior X

MCg:    In general I want to do 7:___:___:___:___:___:___:1: do not want to do what Referent A thinks I should do

NB:     Referent A would think that my performing Behavior X would be Good +3:___:___:___:___:___:-3: Bad

While the measure of NB is not i6 the traditional form, it is consistent with Fishbein's (1975, p. 315) conceptualization of the variable. As seem in Table 3, the results are consistent with Fishbein's theorizing. In a similar study by Glassman and Birchmore (1974), sixty females who were introductory psychology students at the University of Illinois during the Fall of 1972 were asked to fill out a questionnaire which dealt with (1) various components of the intention model for several contraceptive behaviors: use of the birth control pill, use of a diaphragm, use of the rhythm method, use of an I.U.D., asking their boyfriend/husband to obtain a vasectomy, obtaining contraceptive foam and asking their boyfriend/husband to obtain a condom and (2) the following elicited referents: physician, mother, father, friend, planned parenthood, priest, husband/ boyfriend and women's magazines. In addition, motivation to comply was measured at three levels: general (MC_g), moderate (MC_m) and specific (MC_s).

TABLE 3

Of relevance to this discussion is the wording of the following questions:

SN:    Others who are important to me think I should +3:___:___:___:___:___:-3: should not perform Behavior X

NB:     Referent X thinks that  I should +3:___:___:___:___:___:-3: I should not perform Behavior X

MC_g:    In general I want to do 7:___:___:___:___:___:___:1: do not want to do what Referent X thinks I should do

MC_m:    With respect to sexual behavior I want to do 7:___:___:___:___:___:___:1: do not want to do what Referent X thinks I should do

MC_s:    With respect to matters of birth control I want to do 7:___:___:___:___:___:___:1: do not want to do what Referent X thinks I should do

TABLE 4

As seen in Table 4, the results generally support the notion that SN is determined by the sum of the normative beliefs weighted by the general motivation to comply.

While a specific motivation to comply may be more appropriate given the above framework, there is the possibility that questions using an MC_s format will be responded to in terms of the respondent's intention and his perception of the desires of others. If the respondent intends to perform the behavior and views the referent as thinking that he should perform the behavior, he will be motivated to comply with the referent regarding the performance of the behavior. Likewise, if the respondent intends to perform the behavior and he feels that the referent does not want him to perform it, he will not be motivated to comply with the referent regarding the performance of the behavior.

It would seem that based on the previous discussion both MC_g and MC_s are inappropriate measures of the motivation to comply. Returning to Table 4, it appears that from an empirical point of view it makes little difference as to whether the motivation to comply is measured at a general, moderate or specific level.

Another issue pertaining to the motivation to comply is whether or not it should be used as a weight for SN. Again, Fishbein has argued that the motivation to comply with "important others," irrespective of the level of specificity, would merely reflect the regression coefficient of the normative component. Some evidence relating to this question comes from the Glassman and Birchmore (1974) study. Table 5 reports the average multiple regression coefficients for the seven intentions studied.

TABLE 5

AVERAGE MULTIPLE REGRESSION COEFFICIENTS

It can be seem that the addition of MC irrespective of the level of specificity does nothing to improve the predictability of the model. As an additional note, all multiple regression coefficients were significant except those dealing with the use of the diaphragm. These non-significant findings were due, in part, to the lack of variability in the intention to perform the behavior.

ADDITIONAL CONSIDERATIONS

A final point has to do with the way in which the motivation to comply is phrased. Usually respondents are asked whether they "want to do" or "do not want to do" what a particular referent thinks that person should do. If scored from +3 (want to comply) to -3 (do not want to comply) a spite model is assumed. That is, if the respondent feels that Referent A thinks he should not perform the behavior (NB = -3), and he is not motivated to comply with Referent A (MC = -3), Referent A will contribute positively toward his intention to perform the behavior (-3 x -3 = 9). If scored from +6 (want to comply) to 0 (do not want to comply), the fact that the respondent does not want to comply with referent A (MC = 0) who thinks that he should perform the behavior (NB = +3) implies that the wishes of Referent A make no contribution to the respondents intention to perform the behavior (+3 x 0 = 0). Research to date indicates these different methods of scoring have little influence on the regression weights and multiple correlation coefficient.

SUMMARY

REFERENCES

Icek Ajzen, "Attitudinal vs. Normative Messages: An Investigation of the Differential Effects of Persuasive Communications on Behavior," Sociometry, 34(1971), 263-280.

Icek Ajzen and Martin Fishbein, "The Prediction of Behavior from Attitudinal and Normative Variables," Journal of Experimental Social Psychology, 6(1970), 466-487.

Frank S. Bourne, "Different Kinds of Decisions and Reference-group Influence,: in P. Bliss (ed.), Marketing and the Behavioral Sciences (Boston: Allyn and Bacon, 1963).

Joel B. Cohen, "An Interpersonal Orientation to the Study of Consumer Behavior," Journal of Marketing Research, 4(1967), 270-278.

Joel B. Cohen and Arnold M. Barban, "An Interactive Consumer-Product Typological System: A Progress Report and Partial Evaluation," Working Series in Marketing Research, College of Business Administration, Penn State University, 1970, Paper No. 12.

Martin Fishbein, "Attitudes and the Prediction of Behavior,'' in Martin Fishbein, ed. Readings in Attitude Theory and Measurement. New York: John Wiley and Sons, Inc., 1967, 477-492.

Martin Fishbein and Icek Ajzen, Belief, Attitude, Intention and Behavior, An Introduction to Theory and Research, (Reading, Mass.: Addison-Wesley, 1975).

Nancy Fitzhenry and Myron Glassman, "The Prediction of Intention," Unpublished Manuscript, University of Illinois, 1974.

John French and Bertram Raven, "The Bases of Social Power," in D. Cartwright, ed., Studies in Social Power, (Ann Arbor: University of Michigan Press, 1967).

Myron Glassman, "The Effects of Personality and Demographic Factors on the Formation of Attitudes Towards Convenience Goods," Unpublished masters thesis, University of Illinois, 1971.

Myron Glassman and Melinda Birchmore, "The Relationship Between Subjective Norms and Normative Beliefs," Unpublished Manuscript, University of Illinois, 1974.

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