Internal Control Index

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

Comments: The 28-item ICI was developed in four stages and was constantly revised based upon the results of each stage of development. It has two stable factors, internal consistency, norms for demographic categories from college students, and convergent validity.

Scale Construction: The pretesting stage consisted of identifying those aspects related to internal locus of control (autonomy, cognitive processing, delay of gratification, resistance to influence attempts, and self-confidence). Items were developed based on clarity and conciseness. The tryout test was administered to a sample of 548 junior college, continuing education, college, and university students. After item analysis and factor analyses, 28 items were selected for the field test administration, which included 684 people similar to the tryout sample. Analyses of variance, item analysis, and factor analyses were conducted to further refine the ICI.

Sample: The replication sample consisted of 133 students from Gainesville Junior College.

Reliability: Alpha coefficients of 0.84 for the field test and 0.85 for the Gainesville replication study were reported. Item total-score correlations for both samples are provided.

Validity: Convergent validity was established by correlating the ICI with Mirels’ Factor I of Rotter’s I-E Scale (significant at the 0.001 level).

Factor Analysis: A varimax rotation with both the field test sample and the Gainesville Junior College replication sample (133 students) resulted in a two-factor solution. The two factors are confidence in one’s own ability and autonomous behavior. For the field test, 14 items loaded on confidence in one’s own ability (3, 4, 5, 7, 9, 10, 13, 15, 16, 18, 20, 21, 25, and 28), whereas 13 items loaded on the same factor for the Gainesville replication sample (1, 3, 7, 9, 10, 12, 13, 15, 16, 19, 20, 23, and 28). For the field test, 13 items loaded on autonomous behavior (2, 6, 8, 11, 12, 14, 17, 19, 22, 23, 24, 26, and 27), whereas 14 items loaded on the same factor for the Gainesville replication sample (1, 2, 6, 8, 11, 14, 16, 18, 20, 21, 22, 24, 26, and 27).

Data Analysis: Field test means and standard deviations on the ICI are presented by age group, sex, race, educational level, and socioeconomic level.


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.

Internal Control Index

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: Rarely = 5; Occasionally = 4; Sometimes = 3; Frequently = 2; and Usually = 1. The scoring is reversed for the following items: 3, 5, 7, 9, 10, 12, 13, 15, 16, 18, 20, 21, 25, and 28.