Development of a Brief Version of the Pathological Narcissism Inventory

Abstract

With theoretical and empirical interest in narcissism growing, there is a need for brief measures of pathological narcissism that can be used more practically while assessing the construct comprehensively. Data from four samples (total n = 3,851) collected across two separate research groups and representing undergraduate, community, and clinical populations was used to establish the reliability, validity, and utility of the Brief-Pathological Narcissism Inventory (B-PNI). Item response theory and confirmatory factor analyses were used to determine the best-performing 28 items from the original PNI and ensure that the B-PNI exhibited a factor structure consistent with the original PNI. Items were retained for all seven pathological narcissism facet scales. Additional results also support the criterion validity of the B-PNI, suggesting it can be used in place of the original PNI to assess the various facets of pathological narcissism effectively and without loss of information, which may enhance the ability of researchers to investigate pathological narcissism in future work.

For a variety of reasons, research on pathological narcissism was rather limited for quite some time (see Morey & Stagner, 2012). One of the primary barriers to a constructive program of research was the lack of a well-validated measure that comprehensively assessed the facets of pathological narcissism (Cain, Pincus, & Ansell, 2008; Ronningstam, 2009). Indeed, a substantial amount of previous research has relied on the Narcissistic Personality Inventory (NPI; Raskin & Hall, 1979), which can be better understood as a measure of predominantly “normal” or “adaptive” narcissism (e.g., Roche, Pincus, Lukowitsky, Ménard, & Conroy, 2013). In fact, combined with evidence of its inconsistent psychometric properties (e.g., Corry, Merritt, Mrug, & Pamp, 2008; del Rosario & White, 2005), the NPI's utility in clinical research and/or decision-making is questionable (Ackerman, Donnellan, Roberts, & Fraley, in press; Vater et al., 2013).

To address the need for a comprehensive measure of pathological narcissism, Pincus and colleagues created the Pathological Narcissism Inventory (PNI; Pincus et al., 2009), composed of seven facet scales (three contributing to a Grandiosity composite and four to a Vulnerability composite). Growing evidence supports the reliability of PNI scores and the validity of their interpretations (see Pincus, 2013). For example, PNI composite scores show expected associations with clinically relevant criteria such as depression, self-esteem variability, interpersonal problems, self-harm/suicidality, stalking behavior, homicidal ideation, aggression/violence, pathological gambling, and mental health service utilization (e.g., Ellison, Levy, Cain, Ansell, & Pincus, 2013; Ménard & Pincus, 2012; Pincus et al., 2009; Zeigler-Hill & Besser, 2013). However, at 52 items, the length of the PNI may prohibit its inclusion in some projects.

Our goal was to develop a brief but sound measure of pathological narcissism at the facet level, as it is theorized to be a multi-componential and rather heterogeneous construct (e.g., Cain et al., 2008). Given its demonstrated utility, we used the PNI as a basis for our work. Using data from four samples and collected by two separate research groups, we (1) determined which items on the PNI ought to be retained on a brief measure, (2) explored the Brief-PNI's (B-PNI) factor structure, and (3) examined the B-PNI's associations with theoretically relevant external correlates, with reference to those exhibited by the full PNI.

Given their theoretical relevance to narcissism, we specifically examined the B-PNI's associations with self-conscious emotions, as well as features of depression, anxiety, and psychopathy. Regarding self-conscious emotions, hubristic pride and shame are thought to be central to the development/maintenance of narcissism (e.g., Schoenleber & Berenbaum, 2012; Tracy, Cheng, Robins, & Trzesniewski, 2009), but authentic pride and guilt are expected to be negatively or not associated with pathological narcissism, given their adaptive nature. Also, existing theories (e.g., Pincus, Cain, & Wright, 2014; Ronningstam 2011b) and research (e.g., Besser, Zeigler-Hill, Pincus, & Neria, 2013; Ellison et al., 2013; Kealy, Tsai, & Ogrodniczuk, 2012; Tritt, Ryder, Ring, & Pincus, 2010) suggests both grandiose and vulnerable features of pathological narcissism are related to greater mental health concerns, such as depression and anxiety. In addition, there is considerable conceptual overlap between narcissism and psychopathy; based on past work (e.g., Fossati et al., 2014; Schoenleber, Sadeh, & Verona, 2011) we thus expected that B-PNI scores would generally be positively associated with the interpersonally callous/manipulative traits of Factor 1 psychopathy, as well as with the disinhibited, socially irresponsible, and reactively aggressive behavior of Factor 2 psychopathy (see Hare, 1991).

Method

Participants

Sample 1

Participants in Sample 1 were 2,862 adult college students (57.3% female; M age = 19.4 years [SD = 1.8]) at a large university in the Northeastern U.S. who completed an online survey in exchange for course credit. The majority of participants identified as White (84.5%), followed by Asian (6.3%), Black (4.4%), and Latino (3.8%).

Sample 2

Participants in Sample 2 were 348 community members (73.9% female) from a large Midwestern city who participated in a larger project on personality in health- and risk-related behavior. Age of participants ranged from 18 to 84 (M age = 28.7 years [SD = 13.1]). The majority of participants (68.4%) identified as White American, with 12.6% Asian American, 6.6% African American, 3.4% Multiracial, 2.9% Hispanic/Latino(a), and 6.1% “Other.”

Sample 3

Participants in Sample 3 were 581 undergraduate introductory psychology students (47.5% female; M age = 19.0 years [SD = 1.7]) at a large university in the Northeastern U.S., all of whom received course credit. The sample was predominantly White American (89.6%), followed by 6.2% Asian American, 3.2% African American, 0.9% Native Hawaiian, and < 0.1% Native American.

Sample 4

Participants in Sample 4 were 60 patients (85.2% female; M age = 35.7 years [SD = 12.0]) recruited from a large rural community outpatient psychotherapy clinic in the Northeastern U.S. The sample was predominantly White American (91.8%), followed by 4.9% African American, 1.6% Asian/Pacific Islander, and 1.6% describing themselves as “Other.”

Measures

Narcissism

Participants in all samples completed the 52-item PNI (Pincus et al., 2009). We calculated composite and facet scores, where Grandiosity was composed of Exploitativeness, Self-Sacrificing Self-Enhancement, and Grandiose Fantasy; Vulnerability was composed of Contingent Self-Esteem, Hiding the Self, Devaluing, and Entitlement Rage (Wright, Lukowitsky, Pincus, & Conroy, 2010). Internal consistency and descriptive statistics are provided in Table 1.

Table 1.

Internal Consistencies and Descriptive Statistics for the Facet Scales of the Full and B-PNI

	Internal Consistency (α)				Mean (SD)
	Full PNI		B-PNI		Full PNI		B-PNI		Items Retained
Sample:	1	2	1	2	1	2	1	2
Grandiosity	.87	.90	.83	.86	2.8 (.68)	2.9 (.71)	2.7 (.74)	2.9 (.75)
Exploitativeness	.78	.80	.79	.80	2.4 (.90)	2.6 (.83)	2.4 (1.00)	2.5 (.89)	4, 10, 15, 23
Self-Sacrificing Self-Enhancement	.75	.80	.71	.75	2.9 (.76)	3.1 (.83)	2.9 (.83)	3.1 (.88)	22, 25, 33, 39
Grandiose Fantasy	.87	.89	.83	.85	2.9 (.99)	3.1 (.99)	2.8 (1.09)	3.0 (1.06)	26, 31, 42, 45
Vulnerability	.96	.96	.93	.93	2.1 (.81)	2.6 (.77)	1.9 (.89)	2.5 (.84)
Contingent Self-Esteem	.94	.94	.88	.87	2.1 (1.03)	2.5 (.96)	2.0 (1.13)	2.4 (1.03)	8, 30, 32, 36
Hiding the Self	.81	.83	.82	.82	2.4 (.90)	3.1 (.89)	2.1 (1.07)	2.9 (1.05)	9, 28, 46, 50
Devaluing	.89	.89	.85	.85	1.7 (.94)	2.3 (.93)	1.6 (.98)	2.2 (.95)	17, 21, 27, 34
Entitlement Rage	.88	.87	.81	.81	2.1 (.92)	2.5 (.85)	2.0 (1.01)	2.4 (.93)	12, 18, 37, 38

Note: PNI = Pathological Narcissism Inventory.

Note: Item numbers provided are with reference to the full version of the PNI.

All participants completed the NPI-16 (Ames, Rose, & Anderson, 2006), indicating which of two statements best described them, representing a narcissistic response and a nonnarcissistic response. Additionally, as a broad measure of vulnerable narcissism, Samples 2 and 4 completed the Hypersensitive Narcissism Scale (HSNS; Hendin & Cheek, 1997). Participants rated how characteristic each of 10 statements was of them (“My feelings are easily hurt by ridicule or the slighting remarks of others”) on a 5-point scale. Alphas are presented in Table 2.

Table 2.

Associations of the Full and B-PNI with Theoretically Relevant External Correlates

			B-PNI (Full PNI)
	Sample	α	GRAN	EXP	SSSE	GF	VULN	CSE	HS	DEV	ER
Narcissism
NPI-16	1	.70	.35 (.32)	.50 (.52)	.10 (.07)	.18 (.20)	.11 (.10)	.01 (.02)	.02 (.04)	.09 (.07)	.27 (.27)
	2	.71	.23 (.22)	.34 (.33)	.06 (.06)	.16 (.17)	.16 (.15)	.08 (.11)	.04 (−.01)	.18 (.18)	.25 (.25)
	3	.68	.34 (.34)	.51 (.54)	−.02 (−.04)	.16 (.21)	.10 (.08)	−.02 (.00)	.04 (.03)	.06 (.04)	.25 (.23)
	4	.78	.34 (.35)	.41 (.42)	.11 (.06)	.27 (.33)	.11 (.07)	.03 (.06)	−.06 (−.14)	.16 (.06)	.19 (.22)
HSNS	2	.78	.30 (.29)	.12 (.10)	.24 (.20)	.33 (.34)	.59 (.62)	.55 (.58)	.48 (.43)	.50 (.54)	.50 (.54)
	4	.84	.44 (.56)	.16 (.22)	.37 (.47)	.47 (.54)	.49 (.56)	.63 (.64)	.44 (.45)	.00 (.07)	.35 (.32)
Self-Conscious Emotion Dispositions
TPFS
Authentic	3	.85	−.04 (.00)	−.03 (.03)	.02 (.04)	−.06 (−.05)	−.32 (−.33)	−.36 (−.38)	−.26 (−.20)	−.18 (−.22)	−.15 (−.19)
Hubristic	3	.85	.21 (.19)	.24 (.24)	.04 (.02)	.14 (.15)	.24 (.23)	.20 (.19)	.10 (.05)	.23 (.23)	.25 (.26)
TOSCA
Guilt	3	.80	.02 (.06)	−.22 (−.22)	.24 (.29)	.08 (.08)	−.01 (.02)	.05 (.05)	.04 (.07)	−.05 (−.01)	−.08 (−.08)
Shame	3	.79	.09 (.12)	−.20 (−.22)	.24 (.27)	.20 (.18)	.39 (.43)	.39 (.43)	.30 (.29)	.30 (.34)	.23 (.26)
ESS	4	.94	.28 (.28)	.13 (.15)	.24 (.28)	.25 (.21)	.37 (.39)	.35 (.42)	.26 (.17)	.09 (.17)	.37 (.31)
Clinically Relevant Outcomes
MASQ
Anhedonia	2	.95	.09 (.07)	.00 (−.04)	.05 (.00)	.15 (.14)	.49 (.51)	.48 (.51)	.47 (.39)	.43 (.47)	.30 (.33)
Anxiety	2	.93	.22 (.19)	.22 (.19)	.11 (.09)	.18 (.18)	.46 (.45)	.42 (.48)	.35 (.26)	.45 (.48)	.38 (.39)
SRP-II
Interpersonal	2	.86	.49 (.43)	.62 (.59)	.21 (.19)	.35 (.34)	.35 (.34)	.22 (.25)	.22 (.19)	.36 (.33)	.42 (.44)
Coldhearted	2	.69	−.02 (.09)	.23 (.19)	−.23 (−.27)	−.03 (−.09)	.11 (.06)	.01 (.01)	.02 (−.07)	.12 (.15)	.22 (.19)
Disinhibition	2	.77	.27 (.26)	.31 (.29)	−.05 (−.06)	.15 (.12)	.32 (.29)	.25 (.24)	.16 (.05)	.36 (.35)	.35 (.35)
Fearlessness	2	.77	.17 (.13)	.33 (.33)	.08 (.05)	.23 (.25)	.19 (.18)	.11 (.15)	.13 (.10)	.23 (.24)	.18 (.16)

Note: All boldface correlations significant at 99% Confidence Interval for the respective sample: +/−.05 for Sample 1, +/−.14 for Sample 2, for Sample 3, +/−.33 for Sample 4.

Note: None of the pairs of correlations were statistically different, based on 99% Confidence Intervals (CIs) around the B-PNI coefficients. CIs were found by transforming rs to Fisher's z', determining the CI around z', and then back-transforming to rs. Full PNI coefficients outside the CI are statistically different from those of the B-PNI.

Self-Conscious Emotion Dispositions

Participants in Sample 3 completed the Trait Pride Facet Scales (TPFS) to assess general tendencies to experience authentic pride and hubristic pride (Tracy & Robins, 2007). Participants rated the extent to which pride-related terms (e.g., “accomplished,” “arrogant”) characterize them on a 5-point scale. These participants also completed the Test of Self-Conscious Affect (TOSCA; Tangney, Dearing, Wagner, & Gramzow, 2000) to assess propensities for guilt and shame. This measure uses 16 brief scenarios and asks participants to separately rate a guilt response and a shame response on a 5-point scale.

In addition, the participants in Sample 4 completed the Experiences of Shame Scale (ESS; Andrews, Qian, & Valentine, 2002), which assesses trait shamefulness. Participants responded to 25 questions regarding shame (“Have you avoided contact with anyone who knew you said something stupid?”) on a 4-point scale.

Clinically Relevant Outcomes

Participants in Sample 2 completed the Mood & Anxiety Symptoms Questionnaire (MASQ; Watson & Clark, 1991) to assess past week anhedonic depression and anxious arousal. The MASQ includes 39 items (e.g., “Felt like I had nothing to look forward to;” “Heart was pounding or racing”) that are rated on a 5-point scale.

Additionally, Sample 2 completed the Self-Report Psychopathy scale (SRP-II; Hare, Harpur, & Hemphill, 1989). Following Lester, Salekin, and Sellbom (2013), we calculated scores reflecting four factors: interpersonal (tendencies for dominance, manipulation, and arrogance), coldheartedness (lack of concern for others; limited socially responsive emotion), disinhibition (impulsive and irresponsible behavior), and fearlessness (reckless behavior and thrill-seeking). Whereas the interpersonal and coldheartedness factors are representative of features of Factor 1 psychopathy, disinhibition and fearlessness are more representative of Factor 2 psychopathy.

Results

Item Retention and the Structure of the B-PNI

First, item response theory (IRT) analyses based on the generalized partial credit model (Muraki, 1992) were completed using data from Samples 1, 3, and 4.¹ This combined dataset was randomly split into halves (A and B), and the analyses were conducted separately for each half in order to cross-validate the results. Items were selected based on their item information functions, discriminations, and fit. Specifically, best-performing items are those with greater reliability (i.e., high maximum, information functions with unimodal distribution), that differentiate well between respondents with different trait levels (i.e., high discrimination), and produce parameter estimates that do not differ significantly across subgroups generated by median-split (i.e., good item fit, based on a graphical model check with 95% confidence band for any significant likelihood ratio test; Andersen, 1973). Information functions and discriminations were prioritized in our decision-making, as item fit is sample-size dependent. For each facet scale, we sought to identify the four best-performing items to retain on the B-PNI; choosing four items ensured that our latent factors were over-identified (see Brown & Moore, 2013).

Separate IRT analyses in Half A and in Half B suggested retaining the same four items for the Exploitativeness, Hiding the Self, and Entitlement Rage facet scales (see Supplementary Table 1). For the remaining facets, additional analyses were required. IRT analyses in Half A and in Half B differed by one item for three scales (Self-Sacrificing Self-Enhancement, Grandiose Fantasy, and Devaluing) and by two items for Contingent Self-Esteem. Ultimately, IRT analyses identified 16 possible combinations of item sets for the B-PNI. To promote fidelity with the PNI, we used confirmatory factor analyses (CFA) to determine which combination of facet scale item sets for the B-PNI best retained the higher-order factor structure of the PNI (e.g., Fossati et al., 2014; Tritt et al., 2010; Wright et al., 2010).² Specifically, in Samples 1 and 2 separately (to cross-validate across research groups), we ran item-level CFAs in AMOS 20, using maximum-likelihood estimation to test models with two oblique higher-order factors: (1) Grandiosity, composed of Exploitativeness, Self-Sacrificing Self-Enhancement, and Grandiose Fantasy, and (2) Vulnerability, composed of Contingent Self-Esteem, Hiding the Self, Devaluing, and Entitlement Rage. For each of the 16 models, some error variances were allowed to correlate freely (i.e., error variances for items with strong conceptual similarity and high modification indices when using Sample 1 data, see Brown & Moore, 2013). No more than one pair of items was allowed to correlate for a given facet scale, to permit overidentification of each latent factor (see Kenny, Kashy, & Bolger, 1998).

Multiple indices of fit were considered. As the most commonly reported measure of model fit, we ran a chi-squared test in each sample (χ²/df = 10.92 and 2.28, ps < .001, for Sample 1 and Sample 2, respectively); however, chi-squared tests overestimate the lack of fit at larger sample sizes such as ours (Bollen, 1989). As such, to facilitate comparisons with past work on the PNI (e.g., Wright et al., 2010) and in line with recommendations (e.g., Hu & Bentler, 1999), we also considered additional fit indices. All indices fell within acceptable limits (see Hu & Bentler, 1999): comparative fit index (Sample 1 = .916, Sample 2 = .914), the Tucker-Lewis index (Sample 1 = .906, Sample 2 = .904), and the root mean square error of approximation with its 90% confidence interval (Sample 1 = .059 [.057-.061], Sample 2 = .061 [.056-.067]). Further, to compare models, we used the Akaike Information Criterion (Akaike, 1973; see Supplementary Table 2), where lower scores reflect better fitting models. Overall, the results of the CFAs converged well, and the final set of items retained for the B-PNI is provided in Table 1. As in prior CFAs, Grandiosity and Vulnerability were correlated in both samples (rs = .55 in Sample 1 and .64 in Sample 2). Of note, we also created a 12-item version of the PNI, capturing only these composites (rs = .52 and .56); further information can be found in our supplementary material.³

Criterion-Related Validity Evidence for the B-PNI

To begin establishing criterion validity, we examined the associations of B-PNI scores with those of other narcissism measures, self-conscious emotions, and some relevant clinical concerns (see Table 2).⁴ First, as expected, Grandiosity was positively associated with the NPI-16 in all samples, with the strongest associations for Exploitativeness (rs .34 to .51). However, Self-Sacrificing Self-Enhancement was generally not significantly associated with the NPI-16, though it loads on PNI/B-PNI Grandiosity. Further, Entitlement Rage was significantly positively associated with the NPI-16 in three samples, though it contributes to PNI/B-PNI Vulnerability. That said, Vulnerability showed expected positive associations with the HSNS. In fact, all facets but Exploitativeness were significantly associated with the HSNS in Sample 2, and all but Exploitativeness and Devaluing were associated with the HSNS in Sample 4.

Next, in line with theory regarding their role in narcissism (e.g., Tracy et al., 2009), hubristic pride was positively associated with all B-PNI scales except Self-Sacrificing Self-Enhancement and Hiding the Self. Further, shame-proneness was positively associated with all facet scales, and trait shame was positively associated with Vulnerability and two of its facets. By contrast, authentic pride was negatively associated with Vulnerability and its facets and not associated with Grandiosity or its facets. Moreover, guilt-proneness was negatively associated with Exploitativeness, but unexpectedly positively related to Self-Sacrificing Self-Enhancement.

Given pathological narcissism's relevance to other psychological problems (e.g., Ellison et al., 2013; Kealy et al., 2012), we then examined the B-PNI's associations with anhedonic depression, anxious arousal, and features of psychopathy. As expected, B-PNI Vulnerability and its facets were positively associated with both anhedonia and anxious arousal. Grandiose Fantasy was also associated with both of these outcomes, and Grandiosity and Exploitativeness were additionally positively associated with anxious arousal. Consistent with expectations based on their shared nomological network (e.g., Schoenleber et al., 2011), the B-PNI exhibited numerous significant positive associations with SRP-II psychopathy factors. Regarding Factor 1 traits, all B-PNI scores were positively associated with the SRP-II Interpersonal factor, and Exploitativeness and Entitlement Rage were positively associated with Coldheartedness (which was also unexpectedly negatively associated with Self-Sacrificing Self-Enhancement). Further, regarding Factor 2 behaviors, all scales but Self-Sacrificing Self-Enhancement were positively associated with Disinhibition, whereas both composites and Exploitativeness, Grandiose Fantasy, Devaluing, and Entitlement Rage were positively associated with Fearlessness.

In addition, we explored whether the B-PNI's associations with these correlates were consistent with those of the full PNI, which would further support its utility in place of the longer measure. Correlation coefficients for the full PNI and B-PNI with each correlate, respectively, were compared by determining the 99% confidence interval (CI) around the B-PNI coefficient; specifically, B-PNI rs were transformed to Fisher's z’, and the CI around z’ was determined before back-transforming to rs. Full PNI coefficients outside the CI are statistically different from those of the B-PNI. No significant differences were found for any external correlate.

Discussion

Using data from four samples, we created a brief version of the PNI, reducing each of the PNI facet scales to four items. Scores for the resultant brief scales demonstrated adequate-to-good internal consistency. Further analyses confirmed that the factor structure of the B-PNI is consistent with that of the full PNI, and the B-PNI exhibited associations with other measures of narcissism, self-conscious emotions, and features of depression, anxiety, and psychopathy that were generally consistent with theory and highly similar to the associations of the full PNI.

At the same time, some of our findings suggest additional avenues for research on the assessment of pathological narcissism, especially as measured by the B-PNI. First, further work on the content of the Grandiosity composite appears warranted. The Exploitativeness scale was generally more strongly associated with the NPI-16 than were other facets (ts from 2.17 to 24.16, ps < .05), with few exceptions (Sample 2: Entitlement Rage t[345] = 1.69; Sample 4: Grandiose Fantasy, Devaluing, and Entitlement Rage ts[57] = 1.11, 1.79, and 1.73, respectively). This may be unsurprising, as tendencies to exploit others are prominently assessed by the NPI. Yet, this difference raises questions about including Exploitativeness along with Self-Sacrificing Self-Enhancement and Grandiose Fantasy in a single Grandiosity factor. Indeed, the scope of the Grandiosity composite on the B-PNI can be improved, such as by developing items that reflect exhibitionism, another interpersonally important feature of grandiosity. Moreover, Self-Sacrificing Self-Enhancement items on the B-PNI could be added or revised; results herein (e.g. negative association with Coldheartedness) suggest some items may reflect genuine altruism, as opposed to apparently altruistic behavior actually aimed at achieving personal gain. Revising items may also help enhance the associations of the Self-Sacrificing Self-Enhancement and Grandiose Fantasy scales with the NPI, bringing them more in line with the associations found for Exploitativeness. In fact, Self-Sacrificing Self-Enhancement and Grandiose Fantasy were significantly more strongly associated with the HSNS than with the NPI-16. Yet, as the NPI appears to assess more adaptive elements of narcissistic grandiosity (e.g., Roche et al., 2013), it is also the case that using the NPI as a benchmark for what constitutes narcissistic grandiosity is admittedly not ideal when developing a measure of pathological narcissism. Overall, however, having found that the number of items needed to assess pathological narcissism at the facet level can be reduced, adding or revising items to improve content coverage is now more feasible.

The development of an informant-report version of the B-PNI would also aid in understanding the impact of narcissism both on the individual and on those who interact with him/her (e.g., Lukowitsky & Pincus, 2013). Given their self-focus and limited empathy and perspective-taking (e.g., Wai & Tiliopoulos, 2012), people with elevated narcissism may have limited awareness of how their self-perceptions/behaviors detrimentally affect others and, in turn, themselves. Overall, we agree with others (e.g., Oltmanns & Turkheimer, 2009) that use of informant-reports is necessary to form a more complete understanding of narcissism. Studies examining discrepancies in self- and informant-reports when using the B-PNI are also needed.

Additionally, work remains to further establish the reliability of B-PNI scores, the validity of their interpretations, and the practical utility of the B-PNI. In particular, future studies are needed that examine the B-PNI's associations with behavioral and clinically important outcomes (e.g., self- and other-directed aggression, mental health care utilization). Additional research is also needed to corroborate the B-PNI's factor structure and associations among more diverse samples, especially as two of our samples had rather restricted age ranges (Samples 1 and 3) and two were predominantly female (Samples 2 and 4).⁵ Indeed, it will also be important to examine model fit in more diverse samples. TLI and CFI values in our samples were acceptable, even given the model's complexity; however, values closer to .95 would have been preferable (see Hu & Bentler, 1999). That said, we also found acceptable fit using an absolute fit index (RMSEA), which does not penalize for model complexity, and all of this was when including the best-performing individual items (based on IRT analyses). Thus, we have achieved our goal of producing as effective a brief measure as possible, balancing overall model fit with individual item functioning. That said, this study was also limited in that none of our samples completed only the B-PNI (Smith, McCarthy, & Anderson, 2000) to allow for examination of the factor structure when employing the B-PNI in its final format. Still, our efforts are consistent with many guidelines considered important when developing brief versions of existing measures (see Smith et al., 2000); we employed an advanced statistical approach (i.e., IRT), did not solely retain items with the highest inter-item correlations (which could narrow content coverage), provided multiple measures of internal consistency, and performed CFAs to explore fidelity with the full PNI.

Some additional limitations should also be mentioned. For one, given the nature of the measure we sought to develop, obtaining a larger clinical sample would have been preferable. Indeed, our only clinical sample (Sample 4) was much smaller than all others and males were underrepresented. Further, we were unable to compare levels of pathological narcissism reported on the B-PNI with those obtained via interview-based measures, or to examine the B-PNI's relations to other diagnostic entities (e.g., other personality disorders).

In sum, we produced a brief, valid, and reliable 28-item version of the PNI, as well as a 12-item version capturing only Grandiosity and Vulnerability (see Supplementary Tables 6 and 7), which we hope may be useful for other researchers interested in assessing pathological narcissism and its facets, especially under time constraints. As further evidence in support of the reliability of the B-PNI's scores and the validity of their interpretations accumulates, especially among clinical samples, we hope that the availability of this measure will be a boon to research on pathological narcissism.