Introduction

The Extramarital Behavioral Intentions Scale (EBIS) is a brief self-report instrument developed to assess an individual’s intention to engage in extramarital behaviors if the opportunity arises. Based on the Theory of Reasoned Action proposed by Fishbein and Ajzen, the scale measures behavioral intentions, which are considered strong predictors of future behavior. The original scale consists of five items and can be completed in approximately one to two minutes.

Description

The EBIS evaluates the perceived likelihood of engaging in five progressively intimate extramarital behaviors:

  • Flirting
  • Light petting
  • Falling in love
  • Sexual intercourse
  • A long-term sexual relationship

Each item is rated on a 7-point Likert scale, ranging from “Certainly No” to “Certainly Yes.”

Purpose

The scale is designed to:

  • Assess intentions toward extramarital behavior.
  • Examine attitudes and relationship dynamics.
  • Investigate predictors of infidelity.
  • Support research on intimate relationships, sexuality, and social behavior.

Administration

The questionnaire is self-administered and requires approximately 1–2 minutes to complete. Respondents rate the probability that they would engage in each behavior if the opportunity presented itself.

Scoring

Scores are obtained by summing all five items. No reverse scoring is required.

Higher total scores indicate stronger intentions to engage in extramarital behaviors.

Interpretation

The EBIS measures behavioral intentions rather than actual behavior. Higher scores suggest greater openness to potential extramarital involvement, while lower scores indicate stronger intentions to remain exclusive within the current relationship.

Results should always be interpreted alongside other psychological, relational, and demographic variables.

Statistical Analysis

Psychometric evaluation of the EBIS commonly includes:

  • Descriptive statistics.
  • Internal consistency (Cronbach’s α).
  • Test–retest reliability.
  • Construct and concurrent validity.
  • Correlation and regression analyses examining associations with relationship satisfaction, sexual permissiveness, jealousy, and intimacy.

Published studies have reported Cronbach’s alpha values ranging from 0.73 to 0.91, demonstrating satisfactory reliability across different populations.

Applications

The EBIS is widely used in research involving:

  • Relationship and marital satisfaction.
  • Couple and family psychology.
  • Sexual behavior research.
  • Social psychology.
  • Behavioral intention studies.

Advantages

  • Very brief and easy to administer.
  • Excellent internal consistency.
  • Strong evidence of construct and concurrent validity.
  • Suitable for large-scale research.

Limitations

The EBIS assesses hypothetical intentions rather than actual infidelity. Responses may also be influenced by social desirability and cultural attitudes toward relationships and sexuality.

References

Buunk, B. (1980a). Extramarital sex in the Netherlands: Motivations in social and marital context.

Fishbein, M., & Ajzen, I. (1975). Belief, Attitude, Intention and Behavior.

Buunk, B. (1981, 1982). Studies on extramarital intentions, jealousy, and social norms.