The Internal Control Index: A Newly Developed Measure of Locus of Control

This paper presents the development of a new measure of locus of control in adults, the Internal Control Index. Locus of control orientation has been found to be related to cognitive processing, motivation, conformity and autonomy, and self-reliance. Previously developed instruments measure external locus of control, have been criticized for format, response set, dimensionality, and low reliability. The study was conducted in four phases: pretesting item development, tryout testing (N = 548), field testing (N = 684), and a replication study with a sample (N = 133) of junior college students. The analyses of the field test and junior college administration indicated an estimated reliability for the ICI of .84, the presence of a strong principal component, two replicable factors, and evidence for convergent validity.