Table 2. Descriptive Statistics.
| Instrument | Variable | Number of Twins | Mean | Standard deviation | |
|---|---|---|---|---|---|
| Self Report Questionnaire | Antisocial | 7814 | 2.13 | 1.57 | |
| Borderline | 7814 | 3.58 | 2.19 | ||
| Histrionic | 7814 | 3.49 | 1.91 | ||
| Narcissism | 7814 | 2.00 | 1.34 | ||
| Structured Interview | Antisocial | 2731 | 0.30 | 0.76 | |
| Borderline | 2731 | 1.00 | 1.46 | ||
| Histrionic | 2731 | 1.04 | 1.35 | ||
| Narcissism | 2731 | 0.88 | 1.24 | ||
| Cronbach Coefficient Alpha | |||||
|
|
|||||
| Instrument | Variable | Number of Twins | Number of Items | Cronbach Coefficient Alpha (raw) | Cronbach Coefficient alpha (standardized) |
|
| |||||
| Self Report Questionnaire | Antisocial | 7814 | 8 | 0.46 | 0.48 |
| Borderline | 7814 | 13 | 0.62 | 0.64 | |
| Histrionic | 7814 | 10 | 0.54 | 0.55 | |
| Narcissism | 7814 | 8 | 0.26 | 0.30 | |