Internal Control Index

Abstract

The Internal Control Index (ICI) is a robust 28-item psychological measure developed by Duttweiler (1984) to assess an individual’s orientation towards internal locus of control. The scale development followed a rigorous four-stage process involving continuous revision, item analysis, and factor analysis. The ICI exhibits strong psychometric characteristics, including high internal consistency (Alpha coefficients of 0.84–0.85), established norms across various demographic categories (primarily college students), and demonstrated convergent validity. It is structured around two stable factors: confidence in one’s own ability and autonomous behavior.

Keywords

Internal Control Index, ICI, Locus of control, Internal control, Psychological measurement, Self-confidence, Autonomy, Convergent validity, Duttweiler.

Authors

P. C. Duttweiler

Purpose

The primary purpose of the Internal Control Index (ICI) is to provide a reliable and valid measure of an individual’s internal locus of control orientation. This orientation reflects the degree to which individuals believe that outcomes in their lives result from their own efforts, abilities, and actions, rather than from external forces such as luck, fate, or powerful others.

The scale was explicitly designed to capture multiple facets associated with a strong internal control belief, moving beyond simpler measures of internality versus externality. It provides researchers and clinicians with a tool to quantify self-determination and perceived control across diverse populations, primarily college students.

Construct

The ICI measures the construct of Internal Locus of Control. This construct is operationalized through five core behavioral and cognitive aspects identified during the scale’s development:

• Autonomy: The ability and desire to act independently and make one’s own decisions.

• Cognitive Processing: The tendency to thoroughly analyze information and consider different perspectives before acting.

• Delay of Gratification: The capacity to postpone immediate rewards for greater future benefits.

• Resistance to Influence Attempts: The ability to maintain one’s position and resist external pressures or coercion.

• Self-Confidence: A belief in one’s own competence and ability to succeed.

The final factor structure further organizes these traits into the two major domains of confidence in one’s own ability and autonomous behavior.

Validity

The convergent validity of the Internal Control Index was successfully established through correlation with an existing, well-regarded measure of control. Specifically, the ICI was correlated with Mirels’ Factor I of Rotter’s I-E Scale. This correlation was reported as statistically significant at the 0.001 level, indicating that the ICI measures a construct highly related to established dimensions of internal control.

The rigorous, multi-stage development process, which included constant revision and refinement based on item and factor analyses across multiple large samples, supports the overall construct validity of the instrument.

Reliability

The Internal Control Index demonstrates high internal consistency, indicating that its items reliably measure the same underlying construct. Reliability was assessed using Cronbach’s Alpha coefficients across two distinct samples:

• For the initial field test sample, the reported Alpha coefficient was 0.84.

• For the Gainesville Junior College replication study, the reported Alpha coefficient was 0.85.

Detailed item total-score correlations were also provided for both the field test and the replication sample, further supporting the scale’s internal reliability.

Factor Analysis

A varimax rotation procedure was conducted on data from both the field test sample and the Gainesville Junior College replication sample (N=133). This analysis consistently yielded a stable two-factor solution for the Internal Control Index. These two orthogonal factors are:

1. Confidence in One’s Own Ability: This factor relates to self-efficacy, belief in personal competence, and comfort in leadership roles.

2. Autonomous Behavior: This factor relates to independence in action and decision-making, resistance to external influence, and self-directed motivation.

While the specific item loadings varied slightly between the two samples, the overall factor structure remained consistent. For the field test, 14 items loaded onto Factor 1 (Confidence) and 13 items loaded onto Factor 2 (Autonomy). For the replication sample, 13 items loaded onto Factor 1 and 14 items loaded onto Factor 2.

Instrument

Test Type: Self-report psychological scale

Format: 28 items, 5-point Likert-type response scale (Rarely, Occasionally, Sometimes, Frequently, Usually)

Language Available: English (Original development)

Population Group: College students and adults in continuing education

Age Group: Late adolescence through adulthood (based on student samples)

Population Details: The initial tryout sample included 548 junior college, continuing education, college, and university students. The field test included 684 individuals similar to the tryout sample. Normative data (means and standard deviations) are available categorized by age group, sex, race, educational level, and socioeconomic level.

Test Methodology: The scale uses a 5-point frequency rating (Rarely=5, Occasionally=4, Sometimes=3, Frequently=2, and Usually=1). Scoring is reversed for 14 items (3, 5, 7, 9, 10, 12, 13, 15, 16, 18, 20, 21, 25, and 28) to ensure high scores consistently reflect a stronger internal locus of control orientation.

Keywords

Internal consistency, Rotter’s I-E Scale, Varimax rotation, Self-efficacy, Psychometrics, Autonomy, College students, Data analysis.

Authors

Author ORCID Identifier: Not provided in source content.

Affiliation Email addresses: Not provided in source content.

Correspondence Address: Not provided in source content.

Permissions & Fee and Test Year

The scale was developed and published in 1984 by P. C. Duttweiler. Information regarding current usage permissions and associated fees is not available in the original source material and must be sought through the original publisher, Educational and Psychological Measurement, or the author.

Reference’s

• Duttweiler, P. C. (1984). The Internal Control Scale: A newly developed measure of locus of control. Educational and Psychological Measurement 44:209–21.

• MacDonald, A. P., Jr. (1973). Measures of internal-external control. In J. P. Robinson and P. R. Shaver (eds.), Measures of social psychological attitudes. Ann Arbor: University of Michigan.

• Mirels, H. L. (1970). Dimensions of internal versus external control. Journal of Consulting and Clinical Psychology 34:226–28.

• Smith, V. L. (2003). Analysis of locus of control and educational level utilizing the Internal Control Index. M.A. Thesis, Marshall University.

• Stachowiak, B. J. (2010). Job satisfaction and locus of control in an academic setting. EdD dissertation, Pepperdine University.

Items of the Internal Control Index

IMPORTANT: The following scale items must be preserved in their original language and must not be changed in any way.

1. When faced with a problem I try to forget it.

2. I need frequent encouragement from others to keep me working at a difficult task.

3. I like jobs where I can make decisions and be responsible for my own work.

4. I change my opinion when someone I admire disagrees with me.

5. If I want something I work hard to get it.

6. I prefer to learn the facts about something from someone else rather than have to dig them out for myself.

7. I will accept jobs that require me to supervise others.

8. I have a hard time saying “no” when someone tries to sell me something I don’t want.

9. I like to have a say in any decisions made by any group I’m in.

10. I consider the different sides of an issue before making any decisions.

11. What other people think has a great influence on my behavior.

12. Whenever something good happens to me I feel it is because I’ve earned it.

13. I enjoy being in a position of leadership.

14. I need someone else to praise my work before I am satisfied with what I’ve done.

15. I am sure enough of my own opinions to try and influence others.

16. When something is going to affect me I learn as much about it as I can.

17. I decide to do things on the spur of the moment.

18. For me, knowing I’ve done something well is more important than being praised by someone else.

19. I let other people’s demands keep me from doing things I want to do.

20. I stick to my opinions when someone disagrees with me.

21. I do what I feel like doing not what other people think I ought to do.

22. I get discouraged when doing something that takes a long time to achieve results.

23. When part of a group I prefer to let other people make all the decisions.

24. When I have a problem I follow the advice of friends or relatives.

25. I enjoy trying to do difficult tasks more than I enjoy trying to do easy tasks.

26. I prefer situations where I can depend on someone else’s ability rather than just my own.

27. Having someone important tell me I did a good job is more important to me than feeling I’ve done a good job.

28. When I’m involved in something I try to find out all I can about what is going on even when someone else is in charge.

Scoring: The response format uses a 5-point frequency scale: Rarely = 5; Occasionally = 4; Sometimes = 3; Frequently = 2; and Usually = 1. Scores are reversed for items 3, 5, 7, 9, 10, 12, 13, 15, 16, 18, 20, 21, 25, and 28, meaning these items contribute positively to the internal control score.