Development and factorial validation of a short version of the narcissism inventory (NI-20).
BACKGROUND
Narcissism is seen as a normal but heterogeneously formed personality variable, ranging from 'grandiosity-exhibitionism' to 'vulnerability-sensitivity'. This article reports the development and factorial validation of a short version of a narcissism inventory.


METHODS
The sample includes data of 4,509 consecutive psychosomatic inpatients. The overall sample was divided in 2 equally sized randomized subsamples. One sample (n = 2,262) was used for exploratory factor analysis (principal component analysis). The other sample (n = 2,265) was used for confirmatory tests of the model fit of the newly built NI-20 version, and to analyze the model fit separately for men and women using structural equation modeling with AMOS software.


RESULTS
The short version (NI-20) consists of 20 items, with items representing almost all of the original 18 subscales and 4 second-order dimensions. The NI-20 possesses properties similar to the NI-90, with a considerable gain in test economy. The 4-factor structure of the NI-20 was confirmed, and reaches good fit indices.


CONCLUSIONS
The NI-20 is an economical instrument with acceptable psychometric characteristics that reflects the heterogeneous aspects of narcissism. A methodological limitation is that the interactions between sociodemographic variables were not included as potential predictors.
Daig
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I
Institute of Medical Psychology, Charité - University Medical Center, Berlin, Germany. isolde.daig@charite.de <isolde.daig@charite.de>
Burkert
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S
Fischer
H F
HF
Kienast
T
T
Klapp
B F
BF
Fliege
H
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009289:Narcissism; D010555:Personality Inventory / Q000592:standards*; D025341:Principal Component Analysis; D012016:Reference Values; D011795:Surveys and Questionnaires / Q000592:standards*