Extramarital Behavioral Intentions Scale

Extramarital Behavioral Intentions Scale‌

BRAM BUUNK,University of Nijmegen, The Netherlands

Several researchers have correlated the incidence of extra- marital sex with variables such as dissatisfaction with the marital relationship, assuming that these factors could be viewed as causes for engaging in extramarital relationships (e.g., Bell, Turner, & Rosen, 1975). In this type of research, however, it is difficult to unravel the direction of causality (Buunk, 1980a). To make a better assessment of the fac- tors that do indeed lead to extramarital sexual involvement, a scale assessing extramarital behavioral intentions was developed, based on Fishbein and Ajzen’s (1975) theoretical perspective. From this perspective, a behavioral intention is defined as the subjective probability that someone will exhibit a certain behavior if the opportunity presents itself. As Fishbein and Ajzen have argued, and have shown in many studies, specific behavioral intentions correlate highly with actual future behavior. Another assumption behind the construction of the scale was that there is a continuum of extramarital sexual involvement, varying from flirting to a long-term sexual relationship, and that such a continuum should be included in the scale.

Description, Response Mode, and Timing

The scale consists of five items. The format for each item is the same. The respondents are asked to indicate for each of the following behaviors the probability of engaging in it, if an opportunity were to present itself: flirting, light petting, falling in love, sexual intercourse, and a long-term sexual relationship with someone other than their partner. The seven response options range from certainly no to certainly yes, with a midpoint formulated as uncertain. Each of the possible answers is spelled out literally. The respondents circle the number corresponding with the answer that best fits the perceived likelihood under consideration. The scale usually requires no more than 1 or 2 minutes for completion.


The items can simply be summed. No reverse scoring is necessary. Higher scores indicate a higher intention to engage in extramarital sexual behaviors.


Although there are slight variations across samples, the Cronbach alpha of the scale is rather high: .91 in a sample more or less representing the general Dutch population and consisting of people with diverse levels of sexual permissiveness (Buunk, 1980a); .73 in a study of people who had all been involved in extramarital relation- ships (Buunk, 1982); .75 in a sample of people in sexually open marriages (Buunk, 1980b), and .87 in a sample of undergraduate students. Over a 3-month period, test-retest reliability in the open marriage sample was r(100) = .70, p<.001. Furthermore, the scale fulfills the requirements of a Guttman scale, with a coefficient of scalability of .78 and a coefficient of reproducibility of .92. The order of the items in the Guttman scale is flirting, falling in love, light pet- ting, sexual intercourse, and a long-term sexual relation- ship (Buunk, 1980a).


There is considerable evidence for the concurrent validity of the scale. In the sample from the average population, it was found that the more extensive the extramarital experience had been during the previous year, the higher the scores on the Extramarital Behavioral Intentions Scale, r(250) = .74, <.001. The scale particularly differentiates between persons high and low in sexual permissiveness. Individuals from the open marriage sample scored much higher on the scale than a sample more or less representative of the average population, t(348) = 22.46, < .001, and also much higher than a sample of undergraduate students, t(478) = 15.16, <.001. Also, the Extramarital Behavioral Intentions Scale clearly discriminates between those whose reference group accepts extramarital sex and those who socialize with others disapproving of such behavior: The scale correlated highly with one’s friends’ approval of extramarital sex and the perceived opportunity for extra- marital sex (Buunk, 1980a).

Construct validity of the scale has been established in several studies showing positive correlations with scales indicating permissive attitudes toward extramarital sex, and negative correlations with scales measuring the oppo- site. Thus, in the sample of individuals from the average population, a negative correlation was established with a scale measuring the desire for an exclusive relationship, r(250) = -.54, <.001, and positive correlations were found with scales reflecting needs for intimacy outside marriage and for relational variety (see Buunk, 1980a). In the same sample, the Extramarital Behavioral Intentions Scale cor- related highly and negatively with a scale measuring moral disapproval of extramarital sex, (250) = -.65, < .001 (cf. Buunk, 1981). Furthermore, in three samples strong negative correlations were found between the scale and a scale for anticipated sexual jealousy (Buunk, 1982). Also, in the sample of persons who had been involved in extra- marital relationships, a positive correlation was found between the Extramarital Behavioral Intentions Scale and a scale for Psychosexual Stimulation developed by Frenken (1976), r(250) = .21, <.001. This last scale measures the tendency to allow sexual perceptions and fantasizing about sexuality versus the tendency to suppress such perceptions and fantasies.

Final evidence for the validity of the Extramarital Behavioral Intentions Scale comes from the open marriage study. Here, among women, a high correlation was found between the scale and their extramarital intentions as perceived by their husbands, r(50) = .53, <.001. The same correlation among men was somewhat lower, but also significant, r(50) = .42, <.001.

Extramarital Behavioral Intentions Scale

Would you engage in the following behavior with another man/woman if the opportunity were to present itself?

  1. flirting

    1. certainly not

    2. probably not

    3. maybe not

    4. uncertain

    5. maybe yes

    6. probably yes

    7. certainly yes

  2. sexual intercourse a
  3. light petting

  4. a long-term sexual relationship

  5. falling in love

a The seven response options are repeated for each item


Address correspondence to Bram Buunk, Department of Psychology University of Groningen Grote Kruisstraat 2/1, 9712 TS Groningen, The Netherlands; e-mail: [email protected]


Bell, R. R., Turner, S., & Rosen, L. (1975). A multivariate analysis of female extramarital coitus. Journal of Marriage and the Family, 37, 375-384.

Buunk, B. (1980a). Extramarital sex in the Netherlands: Motivations in social and marital context. Alternative Lifestyles, 3, 11-39.

Buunk, B. (1980b). Sexually open marriages. Ground rules for countering potential threats to marriage. Alternative Lifestyles, 3, 312-328.

Buunk, B. (1981). De samenhang van attitudes en sociale normen met de intentie tot buitenechtelijke sex [The relationships between extramari- tal behavioral intentions and attitudes and social norms]. Nederlands Tidschrift voor de Psychologie, 36, 165-170.

Buunk, B. (1982). Anticipated sexual jealousy: Its relationships to self-es- teem, dependency and reciprocity. Personality and Social Psychology Bulletin, 8, 310-316.

Fishbein, M., & Ajzen, I. (1975). Belief, attitude, intention, and behavior. Reading, MA: Addison Wesley.

Frenken, J. (1976). Afkeer van seksualiteit [Aversion to sexuality]. Beventer: Van Loghum Slaterus.