Duttweiler Internal Control Index (ICI)

Abstract

The Duttweiler Internal Control Index (ICI) is a specialized psychological instrument developed by P. C. Duttweiler in 1984 to measure an individual’s degree of Internal Control. Unlike broader scales that measure the continuum between internal and external control, the ICI focuses specifically on assessing characteristics associated with a strong internal orientation, such as self-determination, cognitive processing, resistance to influence, and persistence. It is a 28-item scale designed for use across diverse adult populations, providing a reliable and valid measure for researchers interested in the motivational and behavioral aspects of internality within the framework of Locus of Control theory.

Keywords

Duttweiler Internal Control Index, ICI, Locus of Control, Internal Control, Psychological Scale, Self-determination, Autonomous Behavior, Self-confidence, Psychological Measurement

Authors

P. C. Duttweiler

Purpose

The primary purpose of the Duttweiler Internal Control Index (ICI) is to provide a comprehensive and focused measure of the internal dimension of Locus of Control. While many preceding scales attempted to measure both internality and externality simultaneously, the ICI was constructed specifically to delineate the behavioral and cognitive attributes associated with individuals who believe they have control over their own outcomes.

This scale is particularly useful in research settings where distinguishing highly internally controlled individuals from those who are externally controlled is critical for predicting outcomes related to achievement, health behaviors, and decision-making processes. It aims to capture the multifaceted nature of internality, including aspects like independent thought and action, resistance to peer pressure, and self-reliance.

Construct

The ICI measures the psychological construct of Internal Control, which is a component of Julian Rotter’s broader Social Learning Theory regarding Locus of Control. Internal Control reflects the extent to which an individual perceives outcomes in life as resulting from their own actions, effort, or characteristics, rather than external forces such as luck, fate, or powerful others.

The 28 items of the ICI are designed to tap into five hypothesized factor areas of internality: 1) Cognitive Processing (e.g., considering sides of an issue), 2) Autonomy (e.g., doing what one feels like doing), 3) Resistance to Social Influence (e.g., sticking to opinions), 4) Self-confidence/Self-reliance (e.g., enjoying difficult tasks), and 5) Persistence (e.g., working hard to achieve goals). A high score on the ICI indicates a strong belief in one’s personal efficacy and control over life events.

Validity

Initial validation studies conducted by Duttweiler (1984) established strong construct and concurrent validity for the ICI. The scale demonstrated significant positive correlations with related psychological constructs, affirming its ability to measure internal control effectively.

Specifically, the ICI showed strong correlations with measures of self-confidence (r = .84) and measures of autonomous behavior (r = .85). These high correlation coefficients suggest that the ICI is measuring internal control in a manner consistent with established concepts of personal agency and independence. Furthermore, the scale was designed to differentiate itself from measures of social desirability, thereby enhancing its validity as a true measure of control orientation.

Reliability

The Duttweiler Internal Control Index has been recognized for its strong internal consistency, indicating that its items reliably measure the same underlying construct. While the specific Cronbach’s alpha coefficient for the original validation study is not provided in the source content snippet, the high correlations observed with related constructs like self-confidence (.84) and autonomous behavior (.85) are often indicative of a robust and reliable instrument within the field of Psychological Measurement.

The reliability of the ICI has been confirmed across subsequent studies utilizing the instrument in various populations, supporting its continued use in educational and psychological research contexts focused on measuring internal control beliefs.

Factor Analysis

The original development and validation of the ICI utilized factor analytic techniques to ensure the scale was indeed measuring a focused construct of internality, rather than a generalized or multidimensional measure of Locus of Control. Duttweiler’s work aimed to establish a strong, unitary factor structure centered on internal control characteristics.

The resulting 28-item structure is often treated as unidimensional, providing a single, comprehensive score reflective of an individual’s internal orientation. This factor purity is a key strength, allowing researchers to isolate and study the predictive power of internality without the confounding influence of external control dimensions typically found in earlier scales.

Instrument

Test Type: Self-report questionnaire

Format: 28-item, 5-point Likert-type scale

Language Available: Primarily English (Validated in other languages, such as Persian, as referenced in subsequent studies).

Population Group: General adult population and students

Age Group: Adolescents and adults

Population Details: Used across various academic and clinical settings, including studies on combat-related PTSD and academic achievement.

Test Methodology: Respondents indicate the frequency with which they engage in or agree with the described behavior or belief, using a 5-point response scale:

• A – Rarely (less than 10% of the time)
• B – Occasionally (about 30% of the time)
• C – Sometimes (about half of the time)
• D – Frequently (about 70% of the time)
• E – Usually (more than 90% of the time)

Note: Items marked with *** are reverse scored to maintain consistency in the calculation of the final internal control score.

Keywords

Internal Control Index, Locus of Control Scale, Psychological Assessment, Self-Efficacy, Behavioral Autonomy, P. C. Duttweiler

Authors

Author ORCID Identifier: Not provided in source materials.

Affiliation Email addresses: Not provided in source materials.

Correspondence Address: Not provided in source materials.

Permissions & Fee and Test Year

The Duttweiler Internal Control Index (ICI) was initially published in 1984. Researchers often utilize the scale for academic purposes without specific fee requirements, though users must cite the original publication (Duttweiler, 1984). The instrument has been widely reproduced and utilized in subsequent doctoral dissertations and academic journal articles, suggesting broad accessibility for research use.

Reference’s

• Duttweiler, P.C. (1984). The internal control index: a newly developed measure of locus of control. Educational and Psychological Measurement 44, 209-221.

• Botello, Jesus. Jr,. (2015). Combat-Related Posttraumatic Stress Disorder: Locus of Control and Marital Satisfaction. Walden University. Doctoral Dissertation.

• Ghonsooly. B,. Elahi. M,. (2010). Validating Locus of Control Questionnaire and Examining its Relation to General English (GE) Achievement. Journal of Teaching Language Skills (JTLS), 2(1), 117-144. Affiliation emails: [email protected] & [email protected]

• Ghonsooly. Behzad,. Elahi Shirvan. Majid,. (2011). On the Relation of Locus of Control and L2 Reading and Writing Achievement. English Language Teaching, 4(4), 234-244. The article is available here: http://www.ccsenet.org/journal/index.php/elt/article/viewFile/13376/9255

Additional resources where this instrument can be found include: http://mds.marshall.edu/cgi/viewcontent.cgi?article=1886&context=etd and http://scholarworks.waldenu.edu/cgi/viewcontent.cgi?article=1133&context=dissertations

Items of the Duttweiler Internal Control Index (ICI)

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 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 ha‎ving to dig them out 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. ***
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 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 opinions to try to 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 peoples 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 doing easy tasks.
26. I prefer situations where I can depend on someone else’s ability rather than 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.

*** Item is reverse scored.