Abstract
This study examined the reliability and validity of the revised California Psychological Inventory's (CPI) Vector 1 (v.1) scale, a measure of introversion-extraversion. The v.1 and other psycho- logical scales were administered to 345 introductory psychology students. Coefficient alpha for v.1 was .82, and its test-retest reliability after a 5-week interval was .88. Subjects who were more introverted as measured by v.1 reported that they were less sociable, less assertive, more easily embarrassed, had greater social anxiety, and had a more external locus of control than subjects who were more extraverted. It was concluded that v.1 is a valid measure of Gough's introversion-extraversion construct.