What's to stop someone from lying on a personality test to create a certain impression?

It's a loaded question. There are people who who want to project an image about them that is not truly representing them. This conflict is due to extream competitive environment EE live in. A personality mapping test ideally can have "lie detectors" in built. Under stress questions if a person answers a series of differently located questions very inconsistently then we know he/ she is not truthful or has not understood the question correctly. To detect lies an extension questionnaire has to be framed. This is best left to the experts in developing or tweeking the standard tests in psychology. read less

Four responses can be made to this important question. First, just as some people lie in everyday life, some people will lie on personality tests. Surprisingly, however, test-takers lie less often than you might think, even in highly evaluative situations such as employment selection. Although most people can skew their responses when instructed to do so, it has been estimated that only about one out of seven applicants tend to fake their responses during actual employment selection. Second, just as some people are better liars in everyday life, some people are better fakers on personality tests. Successful faking for employment selection requires that the applicant determine (1) which traits are being used in hiring decisions and (2) how to answer items to elevate scores on the appropriate traits. Concerning Point (1), research has shown that for some occupations (e.g., manager), most people can determine which traits are used for hiring, but for others (e.g., truck driver), people have difficulty determining the relevant traits. Concerning Point (2), people can easily manipulate responses on obvious, self-report items, but social insight is required to manipulate the more subtle, self-presentation items. Third, just like telling white lies, "faking" is not always undesirable. Research has shown that successful fakers are more socially insightful and perform better on certain tasks (including managerial judgment) than poor fakers. Also, research has shown that specific kinds of exaggerating or stretching the truth actually provide valid information about personality. Finally, some of the longer, sophisticated personality inventories, such as the California Psychological Inventory (CPI), contain scales for detecting random responding and conscious attempts to look good or to look bad. Research with the CPI scales indicates that attempts to fake good will be screened out 64% of the time, attempts to look bad, 84% of the time, and random responding, 87% of the time . ref. Google Baba read less

A very interesting question. A personality test is done with a specific purpose. Good tests are designed in such a way that it catches you even if you lie and gives a near accurate picture. Also, if we are not suited for a particular job/profile/responsibilities etc, it would be counter productive for us to fake during a test. read less