In this study Julian Rotter, an American psychologist, proposed the idea that individuals differ from each other based on whether they believe that they can control what happens to them.
He called this a person’s “locus of control” or “location of control”. From his perspective people have one of two locus of control, either an internal locus of control or an external locus of control. Someone who exhibits an internal locus of control believe that their own behaviors are directly responsible for the things that happen to them. Meanwhile someone who has an external locus of control would place responsibility of what happens to them on outside forces such as luck, fate or even an omnipotent being. Rotter based his research on a social learning theory perspective.
This means he believed that as a person develops through infancy all the way through childhood the type of reinforcement that they received and the total sum of all your learning experiences determines whether you have an internal or external outlook. He hypothesized two main points. One of which is that the test developed could reliably measure a person’s orientation towards life. Second is that people will present stable differences in their type of perspective based on the same situations. To study this Rotter designed a test with pairs of statements in each question. One statement would emulate an internal locus of control and the other an external locus of control.
He called this test the I-E Scale. At first his test included 60 items. Eventually it was trimmed down to only 23 pairs of statements, 6 of which were filler items designed to hide the true intentions of the test.
Putting his I-E Scale to use Rotter was able to find connections between scores on his test and situations such as gambling and persuasion. With gambling those who were found to be internal were more likely to bet on sure things while those who are external bet money on more risky bets and are more likely to engage in the gambler’s fallacy. Another study conducted by Rotter concluded that internals were more persuasive than externals and they are more resistant to persuasion by others. Other studies conducted by Rotter concluded similar results in various aspects.