Participant group characteristics
| Variable | DTI study | Rest-fMRI study | ||||
|---|---|---|---|---|---|---|
| Non-psychopaths (n = 13) | Psychopaths (n = 14) | p | Non-psychopaths (n = 20) | Psychopaths (n = 20) | p | |
| Demographic | ||||||
| Age | 31.7 (7.9) | 32.9 (6.9) | 0.69 | 31.1 (7.5) | 32.6 (6.8) | 0.53 |
| Race (Cauc/Afr Am) | 12/1 | 10/4 | 0.33 | 18/2 | 15/5 | 0.41 |
| Neuropsychological | ||||||
| IQa | 102.3 (12.5) | 97.9 (11.1) | 0.36 | 101.4 (12.6) | 99.6 (10.2) | 0.63 |
| Digit span back | 7.1 (2.6) | 6.4 (3.3) | 0.57 | 6.9 (2.2) | 6.7 (3.4) | 0.84 |
| Anxiety/Neg affectb | 13.5 (10.7) | 13.2 (7.2) | 0.93 | 11.2 (9.5) | 13.4 (8.3) | 0.44 |
| Psychopathy | ||||||
| PCL-R total | 14.6 (2.7) | 32.2 (1.8) | <0.001 | 14.2 (3.4) | 31.9 (1.7) | <0.001 |
| Factor 1 | 5.3 (1.9) | 12.1 (1.7) | <0.001 | 4.7 (2.1) | 11.8 (1.8) | <0.001 |
| Factor 2 | 7.5 (3.0) | 17.4 (1.4) | <0.001 | 7.9 (3.1) | 17.2 (1.5) | <0.001 |
| Substance abusec | ||||||
| Alcohol | ||||||
| Prevalence | 5/10 | 7/11 | 0.67 | 9/16 | 11/16 | 0.72 |
| Age of onset | 21.0 (5.2) | 17.7 (2.2) | 22.4 (6.5) | 19.0 (3.4) | ||
| Cannabis | ||||||
| Prevalence | 4/10 | 7/11 | 0.39 | 7/16 | 11/16 | 0.29 |
| Age of onset | 19.8 (4.7) | 19.7 (8.6) | 17.9 (4.7) | 19.3 (6.8) | ||
| Cocaine | ||||||
| Prevalence | 2/10 | 3/11 | 0.99 | 3/16 | 6/16 | 0.43 |
| Age of onset | 17, 18 | 16, 16, 26 | 19.7 (2.9) | 20.2 (5.4) | ||
| Stimulants | ||||||
| Prevalence | 1/10 | 2/11 | 0.99 | 2/16 | 4/16 | 0.65 |
| Age of onset | 30 | 20, 23 | 16, 18 | 15, 20, 23, 30 | ||
| Opioids | ||||||
| Prevalence | 2/10 | 2/11 | 0.99 | 3/16 | 6/16 | 0.43 |
| Age of onset | 15, 35 | 16, 20 | 20.7 (5.1) | 21.7 (7.3) | ||
| Sedatives | ||||||
| Prevalence | 0/10 | 1/11 | 0.99 | 1/16 | 2/16 | 0.99 |
| Age of onset | n/a | 20 | 27 | 20/22 | ||
| Hallucinogens | ||||||
| Prevalence | 0/10 | 3/11 | 0.21 | 1/16 | 4/16 | 0.33 |
| Age of onset | n/a | 15, 20, 21 | 20 | 15, 17, 20, 21 | ||
↵aBased on Shipley Institute of Living Scale (Zachary, 1986),
↵bbased on Welsh Anxiety Scale,
↵cbased on diagnosis of abuse or dependence in the Structured Clinical Interview for DSM-IV Disorders (SCID) (First, 2002), which was administered to 10/13 non-psychopaths and 11/14 psychopaths in the DTI study and 16/20 non-psychopaths and 16/20 psychopaths in the rest-fMRI study. p values for race distribution and substance abuse prevalence were computed with Fisher's exact test. All other p values are based on t test (means presented followed by SDs in parentheses). p values were not calculated for substance abuse age of onset due to relatively small sample sizes of abusers for most substances.