Descriptive statistics
The mean (SD) PID-5-BF total score obtained for the full university student sample (N = 7,155) was 16.4 (8.20), with females having a significantly greater (t = -6.80, p < 0.01) mean score, at 17.10 (7.96), than males, at 15.79 (8.32). The mean (SD) PID-5-BF total score obtained for the clinical sample (N = 451) was 29.78 (10.70), with females again showing a significantly greater (t = -4.37, p < 0.01) mean score, at 31.75 (10.98), than males, at 27.41 (9.86). The mean obtained for the clinical sample was significantly greater (t = 26.04, p <0.01) than that obtained for undergraduate student sample. The mean (SD) PID-5-BF total score obtained for the subsample used in the EFA, at 16.29 (8.24)(N = 3,633), was statistically similar (t = -1.34, p = 0.18) to that obtained for the subsample used in the CFA, at 16.55 (8.11)(N = 3,522).
EFA and CFA
EFA supported an exploratory five-factor model and an exploratory six-factor model. The factor designations of the items are compared across these two exploratory models and Krueger et al.’s (2013) previously reported five-factor model [36] in Table 1. In our exploratory five-factor model, five items (8, 9, 11, 15, and 20) did not load into any factor; item 10 was the only item to reach a 0.3 loading weight in the Negative Affect domain, and it loaded with item 19, which had belonged to the Antagonism factor in the previously published model. Our exploratory six-factor model had higher fit indices (CFI = 0.969, TLI = 0.944) than the exploratory five-factor model (CFI = 0.952, TLI = 0.922), with fewer items failing to load on any factor (items 8 and 11). A new factor named Interpersonal Relationships was added to the original five factors. The factor loadings of each item in the exploratory six-factor model are reported in Table 2.
Table 1. Item comparison among three models.
Model
|
Items associated with each factor, F1–6
|
F1
|
F2
|
F3
|
F4
|
F5
|
F6
|
Theoretical five-factor
|
8, 9, 10, 11, 15
|
4, 13, 14, 16, 18
|
17, 19, 20, 22, 25
|
1, 2, 3, 5, 6
|
7, 12, 21, 23, 24
|
–
|
Exploratory five-factor
|
–
|
4, 13, 14, 16, 18
|
17, 22, 25
|
1, 2, 3, 5, 6
|
7, 12, 21, 23, 24
|
10, 19
|
Exploratory six-factor
|
9, 15
|
4, 13, 14, 16, 18
|
17, 20, 22, 25
|
1, 2, 3, 5, 6
|
7, 12, 21, 23, 24
|
10, 19
|
Table 2. Factor loading for the exploratory six-factor model (N = 3,633).
Item
|
Factor
|
NA
|
IR
|
De
|
An
|
Ps
|
Di
|
9. I get emotional easily, often for very little reason.
|
0.70
|
0.05
|
0.00
|
-0.07
|
0.12
|
0.02
|
15. I get irritated easily by all sorts of things.
|
0.50
|
0.00
|
0.23
|
0.10
|
-0.03
|
0.02
|
10. I fear being alone in life more than anything else.
|
0.01
|
0.61
|
-0.02
|
-0.01
|
-0.02
|
0.02
|
19. I crave attention.
|
0.06
|
0.47
|
-0.11
|
0.09
|
0.01
|
-0.00
|
4. I often feel like nothing I do really matters.
|
-0.05
|
0.06
|
0.44
|
0.01
|
0.01
|
0.17
|
13. I steer clear of romantic relationships.
|
0.04
|
-0.11
|
0.36
|
-0.10
|
0.21
|
-0.01
|
14. I’m not interested in making friends.
|
0.06
|
-0.12
|
0.58
|
0.07
|
0.01
|
0.00
|
16. I don’t like to get too close to people.
|
0.04
|
-0.08
|
0.43
|
0.03
|
0.21
|
-0.10
|
18. I rarely get enthusiastic about anything.
|
-0.02
|
0.03
|
0.59
|
-0.01
|
0.12
|
0.02
|
17. It’s no big deal if I hurt other peoples’ feelings.
|
0.04
|
0.01
|
0.28
|
0.43
|
-0.12
|
0.07
|
20. I often have to deal with people who are less important than me.
|
0.08
|
0.14
|
0.06
|
0.30
|
0.23
|
-0.06
|
22. I use people to get what I want.
|
0.01
|
0.02
|
0.05
|
0.61
|
0.03
|
0.10
|
25. It is easy for me to take advantage of others.
|
-0.05
|
0.00
|
-0.02
|
0.65
|
0.22
|
-0.02
|
7. My thoughts often don’t make sense to others.
|
0.04
|
-0.06
|
0.07
|
0.01
|
0.45
|
0.17
|
12. I have seen things that weren’t really there.
|
0.00
|
0.00
|
0.06
|
0.16
|
0.42
|
-0.01
|
21. I often have thoughts that make sense to me but that other people say are strange.
|
-0.02
|
-0.05
|
-0.08
|
0.14
|
0.61
|
0.08
|
23. I often “zone out” and then suddenly come to and realize that a lot of time has passed.
|
0.04
|
0.14
|
0.03
|
-0.14
|
0.52
|
0.10
|
24. Things around me often feel unreal, or more real than usual.
|
-0.00
|
0.10
|
0.05
|
0.02
|
0.63
|
-0.03
|
1. People would describe me as reckless.
|
0.15
|
-0.05
|
-0.15
|
0.06
|
-0.03
|
0.55
|
2. I feel like I act totally on impulse.
|
0.15
|
-0.01
|
-0.01
|
0.01
|
0.02
|
0.56
|
3. Even though I know better, I can’t stop making rash decisions.
|
0.07
|
0.07
|
0.05
|
-0.01
|
0.20
|
0.37
|
5. Others see me as irresponsible.
|
-0.02
|
-0.00
|
0.23
|
0.07
|
0.07
|
0.35
|
6. I’m not good at planning ahead.
|
-0.07
|
0.12
|
0.17
|
-0.14
|
0.00
|
0.46
|
8. I worry about almost everything.
|
0.17
|
0.19
|
0.22
|
0.14
|
0.04
|
0.06
|
11. I get stuck on one way of doing things, even when it’s clear it won’t work.
|
0.06
|
0.16
|
0.24
|
0.05
|
0.12
|
0.21
|
Note. NA, Negative Affect; IR, Interpersonal Relationships; De, Detachment; An, Antagonism; Ps, Psychoticism; Di, Disinhibition.
Bold represents the largest factor loading in each item as well as >0.30.
We chose to pursue analysis of our exploratory six-factor model because it had better model fit indices and fewer items that failed to load than our exploratory five-factor model and because of the significant differences in the Negative Affect domain between our exploratory five-factor model and the theoretical five-factor model. As shown in Table 3, we obtained significantly greater fit indices for our exploratory six-factor model than for the theoretical five-factor model in both our undergraduate student sample and clinical sample.
Table 3. Goodness of fit index values for the compared models.
Model
|
CFI
|
TLI
|
SRMR
|
RMSEA
|
RMSEA 90%CI
|
LO90
|
HI90
|
Normal sample (N = 3,522)
|
|
|
|
|
TFF
|
0.887
|
0.872
|
0.044
|
0.046
|
0.044
|
0.048
|
ESF
|
0.905
|
0.888
|
0.039
|
0.044
|
0.042
|
0.046
|
Clinical sample (N = 451)
|
|
|
|
|
TFF
|
0.868
|
0.848
|
0.061
|
0.053
|
0.048
|
0.059
|
ESF
|
0.904
|
0.886
|
0.060
|
0.047
|
0.041
|
0.054
|
Note. TFF, theoretical five-factor model; ESF, exploratory six-factor model; CFI, comparative fit index, TLI, Tucker-Lewis index; SRMR, standard root mean square residual; RMSEA, root-mean-square error of approximation; LO90/HI90, lower/upper 90% confidence interval of the RMSEA.
MI across populations
As shown in Table 4, we established configural, weak, and strong MI across the normal and clinical samples. However, the acceptable index criteria were not met for strict MI. We allowed the residual variances of items with the largest modification indices to be freely estimated until the △CFI of the last model was £ 0.01. Parameter constraints of items 15, 4, 14, 18, 17, 20, 7, 12, 24 and 5 were released in this process. Subsequently, partial strict MI of our modified six-factor model was supported. Hence, ultimately, our modified six-factor PID-5-BF model achieved configural MI, weak MI, strong MI, and partial strict MI across our normal and clinical samples.
Table 4. Fit indexes of the PID-5-BF for MI across population.
Model
|
S-Bx2
|
df
|
CFI
|
TLI
|
RMSEA
|
△CFI
|
△TLI
|
BIC
|
△RMSEA
|
Configural
|
3013.479*
|
420
|
0.923
|
0.907
|
0.040
|
—
|
—
|
323186.073
|
—
|
Weak
|
3196.737*
|
437
|
0.918
|
0.905
|
0.041
|
-0.005
|
-0.002
|
323230.393
|
—
|
Strong
|
3480.394*
|
454
|
0.910
|
0.900
|
0.042
|
-0.008
|
-0.005
|
323383.756
|
0.001
|
Strict
|
5377.472*
|
477
|
0.855
|
0.846
|
0.052
|
-0.055
|
-0.054
|
325314.743
|
0.010
|
Part.Strict
|
3817.237*
|
467
|
0.901
|
0.892
|
0.043
|
-0.009
|
-0.008
|
323635.095
|
0.001
|
Note. Part.Strict, partial strict invariance by releasing the residuals of items with largest modification indices; the S-Bχ2 = Satorra-Bentler scaled χ2; df, degrees of freedom; TLI, Tucker-Lewis index; CFI, comparative fit index; RMSEA, root-mean-square error of approximation; BIC, Bayesian information criterion.
Reliability
In the normal sample, we obtained a Cronbach’s a of 0.84, a MIC of 0.21 for the PID-5-BF total scale, and domain MICs in the range of 0.29–0.46. Domain subscores correlated significantly with total scores (r = 0.38–0.80, all p < 0.01). With respect to test-retest reliability over a 4-week interval, we obtained a Pearson correlation coefficient of 0.73 for the total scale, with domain correlation coefficients in the range of 0.50–0.67.
For the clinical sample, we obtained a Cronbach’s a of 0.86, a MIC of 0.19 for the total scale, and domain MICs in the range of 0.27–0.58. Similar to our results with the normal sample, we observed significant correlations between the domain subscores and the PID-5-BF total score (r = 0.26–0.78).
Criterion validity
PID-5-BF total scores correlated with scores obtained for the original 220-item PID-5 in our normal population participants (N = 3985, r = 0.93, p < 0.01). Correlation coefficients for each domain were in the range of 0.64–0.86 in the undergraduate student normal sample and in the range of 0.69–0.91 in the clinical patient sample. As shown in Table 5, the Interpersonal Relationships domain showed the greatest correlation coefficient with the Negative Affect domain in both samples. Finally, as shown in Table 6, PID-5-BF domain scores correlated significantly with the six PD dimensions in Section III of the DSM-5 (schizotypal, antisocial, borderline, narcissistic, avoidant, and obsessive-compulsive).
Table 5. Correlations between the PID-5-BF and full-length PID-5.
PID-5-BF domains
|
220-item PID-5 domains
|
NA
|
De
|
An
|
Ps
|
Di
|
TS
|
Normal sample (N = 3,985)
|
|
|
|
|
|
NA
|
0.64**
|
0.35**
|
0.33**
|
0.40**
|
0.52**
|
0.58**
|
IR
|
0.58**
|
0.03
|
0.32**
|
0.26**
|
0.28**
|
0.40**
|
De
|
0.37**
|
0.86**
|
0.30**
|
0.47**
|
0.43**
|
0.62**
|
An
|
0.37**
|
0.40**
|
0.75**
|
0.53**
|
0.43**
|
0.65**
|
Ps
|
0.57**
|
0.49**
|
0.46**
|
0.85**
|
0.54**
|
0.77**
|
Di
|
0.47**
|
0.32**
|
0.27**
|
0.40**
|
0.82**
|
0.57**
|
TS
|
0.75**
|
0.67**
|
0.60**
|
0.77**
|
0.79**
|
0.93**
|
Clinical sample (N = 395)
|
|
|
|
|
|
NA
|
0.69**
|
0.31**
|
0.17**
|
0.30**
|
0.53**
|
0.55**
|
IR
|
0.54**
|
-0.05**
|
0.29**
|
0.23**
|
0.26**
|
0.33**
|
De
|
0.40**
|
0.91**
|
0.12**
|
0.43**
|
0.49**
|
0.65**
|
An
|
0.21**
|
0.30**
|
0.73**
|
0.35**
|
0.27**
|
0.52**
|
Ps
|
0.58**
|
0.50**
|
0.37**
|
0.88**
|
0.55**
|
0.78**
|
Di
|
0.51**
|
0.34**
|
0.20**
|
0.44**
|
0.84**
|
0.62**
|
TS
|
0.76**
|
0.71**
|
0.46**
|
0.74**
|
0.81**
|
0.94**
|
Note. NA, Negative Affect; IR, Interpersonal Relationships; De, Detachment; An, Antagonism; Ps, Psychoticism; Di=, Disinhibition; TS, Total Score. Bold presents the highest correlation coefficient in each row.
**Correlation is significant at the 0.01 level (2-tailed).
Table 6. Correlations between PID-5-BF domains and the six DSM-4 PDs retained in Section III of the DSM-5 and measured by PDQ-4+.
PID-5-BF domains
|
DSM-4 PDs in Section III of the DSM-5
|
STPD
|
ASPD
|
BPD
|
NPD
|
AVPD
|
OCPD
|
Normal sample (N = 7,155)
|
|
|
|
|
|
TS
|
0.35**
|
0.28**
|
0.53**
|
0.39**
|
0.48**
|
0.35**
|
NA
|
0.20**
|
0.18**
|
0.43**
|
0.27**
|
0.33**
|
0.25**
|
IR
|
0.13**
|
0.12**
|
0.23**
|
0.29**
|
0.26**
|
0.19**
|
De
|
0.24**
|
0.05**
|
0.31**
|
0.17**
|
0.36**
|
0.24**
|
An
|
0.29**
|
0.26**
|
0.27**
|
0.33**
|
0.23**
|
0.21**
|
Ps
|
0.39**
|
0.22**
|
0.44**
|
0.34**
|
0.37**
|
0.33**
|
Di
|
0.13**
|
0.28**
|
0.40**
|
0.22**
|
0.32**
|
0.16**
|
Clinical sample (N = 231)
|
|
|
|
|
|
TS
|
0.44**
|
0.40**
|
0.66**
|
0.28**
|
0.43**
|
0.21**
|
NA
|
0.24**
|
0.19**
|
0.43**
|
0.14**
|
0.35**
|
0.21**
|
IR
|
0.11**
|
0.06**
|
0.25**
|
0.30**
|
0.24**
|
0.13**
|
De
|
0.22**
|
0.10**
|
0.43**
|
0.02**
|
0.31**
|
0.12**
|
An
|
0.23**
|
0.36**
|
0.23**
|
0.32**
|
0.07**
|
0.06**
|
Ps
|
0.46**
|
0.30**
|
0.49**
|
0.24**
|
0.22**
|
0.23**
|
Di
|
0.20**
|
0.41**
|
0.46**
|
0.12**
|
0.34**
|
-0.00**
|
Note. NA, Negative Affect; IR, Interpersonal Relationships; De, Detachment; An, Antagonism; Ps, Psychoticism; Di, Disinhibition; TS, Total Score; STPD, schizotypal personality disorder; ASPD, antisocial personality disorder; BPD, borderline personality disorder; NPD, narcissistic personality disorder; AVPD, avoidant personality disorder; OCPD, obsessive-compulsive personality disorder.
Bold means suggested domains of each personality disorder in DSM-5;
**Correlation is significant at the 0.01 level (2-tailed)