Main outcomes
Table
3 shows the prevalence of symptoms (SAPS) and relevance of symptoms at the time of the violent act as rated by treating or admitting clinicians.
The expert witnesses judged that none of the moral cognitions were clearly present (moral cognitions scoring > 3) in one case (1.8%), one moral cognition was present in 16 cases (29.1%), two moral cognitions were present in 24 cases (43.6%), three moral cognitions were present in 13 (23.6%) and four moral cognitions were present in one case (1.8%). No experts found all five domains of moral cognition to be clearly present concurrently in any one case.
Table
2 shows the numbers clearly present for each of the domains of moral cognitions at the time of the violent act, as rated by expert witnesses, patients’ self-ratings, and an independent research clinician.
For expert witnesses, the mean scores and standard deviations for the moral foundations were as follows: ‘care-harm’, 2.03 (SD = 1.74), ‘fairness-injustice’, 3.98 (SD = 2.01), ‘loyalty-betrayal’, 3.47 (SD = 2.07), ‘authority’, 2.65 (SD = 2.05), and ‘purity-disgust’, 2.27, (SD = 1.76).
Of the 51 patients that completed the self-report measure, six indicated that no moral foundation was clearly present (11.7%), 17 indicated that one domain of moral cognition was present (33.3%), 15 indicated that two domains of moral cognition were present (29.4%), five indicated that three domains of moral cognitions were present (9.8%), seven indicated that four domains of moral cognitions were present (13.7%), and one indicated that all five domains of moral foundations were clearly present (2%).
For patients, the mean scores and standard deviations for the five moral cognitions were as follows: ‘care-harm’, 2.92 (SD = 2.09), ‘fairness-injustice’, 3.17 (SD = 2.08), ‘loyalty-betrayal’, 3.11 (SD = 2.15), ‘authority’, 2.98 (SD = 2.27), and ‘purity-disgust’, 2.01, (SD = 1.71).
Hypothesis 1:
H1.1 Psychotic symptoms i.e. delusions and hallucinations, present at the time of the violent act and relevant to acts of violence will
not
be significantly positively correlated with independently rated forms of violence, such as homicide, seriousness of violence, and instrumental-reactive aggression.
H1.2 By contrast, moral cognitions judged to reflect the patient’s thinking and motivation at the time of the violent act will be significantly positively correlated with forms of violence.
Table
4 shows three MANOVA omnibus tests for relationships between all symptoms, all moral cognitions, and severity and forms of violence. In model 1, total SAPS psychopathology score is significantly related to moral cognitions (
p = 0.041, Eta
2 = 0.632). In model 2, instrumental-reactive violence is related to the five moral cognitions (
p < 0.001, Eta
2 = 0.27). In model 3, severity of violence is significantly related to five moral cognitions (
p = 0.032, Eta
2 = 0.17).
Table 4
MANOVA omnibus tests for relationships between total symptom severity scores (SAPS), five moral cognition scores and qualities of violence (instrumental-reactive, severity)
1 | SAPS-total | Five moral cognitions | 0.008 | 1.371 | 140,113 | 0.041 | 0.623 |
2 | Instrumental-reactive | Five moral cognitions | 0.384 | 3.599 | 15,147 | 0.000 | 0.273 |
3 | Severity of violence | Five moral cognitions | 0.384 | 1.603 | 30,178 | 0.032 | 0.174 |
H1.1. The only finding that was contrary to the hypothesis that psychotic symptoms were not correlated with the seriousness of violence and forms of violence, was that delusions of guilt were positively correlated with instrumental aggression (r = .304, n = 55, p = .024). Homicide was not positively correlated with SAPS-rated delusions or hallucinations although delusions of misidentification or doubles approached significance (r = .255, n = 55, p = .060). Seriousness of violence was not positively correlated with psychotic symptoms present or judged to be ‘relevant’ to the act of violence. Instrumental or reactive violence was not positively correlated with any other psychotic symptoms.
H1.2: We found that certain moral cognitions were correlated with seriousness of violence and with forms of violence. Expert rated ‘loyalty-betrayal’ was positively correlated with homicide (r = .310, n = 55, p = .021). Expert rated ‘loyalty-betrayal’ was also positively correlated with seriousness of violence (r = .289, n = 55, p = .032). Expert rated ‘fairness-injustice’ was negatively correlated with instrumental aggression (r = −.424, n = 55, p = .001) i.e. positively with reactive violence. Expert rated ‘loyalty-betrayal’ was negatively correlated with instrumental aggression (r = −.510, n = 55, p = .000) as was expert-rated ‘purity-disgust’ (r = −.329, n = 55, p = .014) i.e. both were positively correlated with reactive aggression.
Hypothesis 2: Moral cognitions will account for forms of violence, when controlling for neurocognition and violence proneness (HCR-20).
Table
5 shows that for each unit change in the rating of ‘loyalty-betrayal’ (rated 1–6) as relevant to the offence, homicide was increased in likelihood by OR of 1.392 (95% CI 1.055–1.837) and this remained significant when adjusted for neurocognition (MCCB) scores or violence proneness (HCR-20-H) scores. No other domain of moral cognition was significantly related to the likelihood of homicide.
Table 5
Homicide versus other violence: binary logistical regression
| | Lower Upper | | Lower Upper | | Lower Upper |
Care | .794 | .571 | 1.104 | .771 | .546 | 1.088 | .769 | .547 | 1.081 |
Fairness | .973 | .746 | 1.268 | .966 | .737 | 1.267 | .979 | .747 | 1.283 |
Loyalty | 1.392 | 1.055 | 1.837 | 1.451 | 1.079 | 1.950 | 1.411 | 1.059 | 1.879 |
Authority | 1.042 | .803 | 1.350 | 1.025 | .785 | 1.338 | 1.028 | .789 | 1.340 |
Purity | .858 | .629 | 1.169 | .823 | .596 | 1.138 | .854 | .623 | 1.171 |
Cornell’s seriousness of violence scale: linear regression |
Moral cognition | Beta | CI 95% | Beta adjusted MCCB | CI 95% | Beta adjusted HCR-20-H | CI 95% |
| | Lower Upper | | Lower Upper | | Lower Upper |
Care | −.257 | −.559 | .044 | −.267 | −.570 | .036 | −.277 | −.575 | .021 |
Fairness | −.052 | −.320 | .216 | −.055 | −.324 | .214 | −.047 | −.312 | .219 |
Loyalty | .260 | .017 | .517 | .275 | .024 | .526 | .263 | .016 | .511 |
Authority | −.026 | −.288 | .236 | −.036 | −.300 | .229 | .-.039 | .-.299 | .222 |
Purity | .002 | −.304 | .307 | −.013 | −.321 | .296 | .003 | .-.300 | .305 |
Cornell’s instrumental-reactive aggression: linear regression |
Moral cognition | Beta | CI 95% | Beta adjusted MCCB | CI 95% | Beta adjusted HCR-20 | CI 95% |
| | Lower Upper | | Lower Upper | | Lower Upper |
Care | .054 | −.126 | .235 | .058 | −.124 | .240 | .060 | .-.122 | .242 |
Fairness | −.283 | −.419 | −.147 | −.282 | −.419 | −.145 | −.285 | −.421 | −.149 |
Loyalty | −.269 | −.402 | −.136 | −.274 | −.407 | −.140 | −.268 | −.402 | −.135 |
Authority | .162 | .015 | .309 | .168 | .020 | .316 | .167 | .019 | .314 |
Purity | −.165 | −.337 | .008 | −.160 | −.335 | .015 | −.165 | −.338 | .008 |
For each unit change in the rating of ‘loyalty-betrayal’ (1–6) as relevant to the offence, the score on the Cornell seriousness of violence scale increased by one unit i.e. more serious. This also remained significant even when adjusted for neurocognition (MCCB) or violence proneness (HCR-20-H).
Table
5 also shows that for each unit change in the rating of ‘fairness-injustice’ or ‘loyalty-betrayal’ (1–6) as relevant to the offence, the score on the Cornell instrumental-reactive aggression scale decreased i.e. more reactive, and that for each unit change in the rating for authority (1–6) as relevant to the offence, the Cornell reactive-instrumental violence scale increased i.e. more instrumental. This also remained significant even when adjusted for neurocognition (MCCB) or violence proneness (HCR-20-H).
Hypothesis 3: Specific moral cognitions will be significantly positively correlated with specific psychotic symptoms present at the time of the violent act or judged to be relevant to the violent act. The correlations will have face validity, by which we mean there will be causal and meaningful connections
within the limits of mediation analysis
i.e. that the meaningful explanation makes sense.
We found that specific moral cognitions rated by ‘expert witnesses’ correlated positively with specific delusions or hallucinations. The moral cognition involving ‘care-harm’ correlated positively with religious delusions (
r = .421,
n = 55,
p = .001); ‘relevant’ religious delusions (
r = .443,
n = 55,
p = .001); grandiose delusions (
r = .281,
n = 55,
p = .038); and ‘relevant’ grandiose delusions (
r = .279,
n = 55,
p = .039). ‘Care-harm’ also correlated with ‘relevant’ delusions of guilt (
r = .438,
n = 55,
p = .001), but not with other delusions or hallucinations. All are in keeping with the factor analysis of Peralta [
51] (Table
1).
The moral cognitions involving ‘fairness-injustice’ correlated positively with delusions of persecution (r = .391, n = 55, p = .003); ‘relevant’ persecutory delusions (r = .427, n = 55, p = .001), somatic delusions (r = .316, n = 55, p = .019); ‘relevant’ somatic delusions (r = .304, n = 55, p = .024); delusions of mind reading (r = .282, n = 55, p = .037); ‘relevant’ delusions of mind reading (r = .282, n = 55, p = .037); somatic or tactile hallucinations (r = .270, n = 55, p = .046); ‘relevant’ somatic or tactile hallucinations (r = .304, n = 55, p = .024), and no other delusions or hallucinations.
The moral cognitions involving ‘loyalty-betrayal’ correlated positively with delusions of persecution (r = .355, n = 55, p = .008); and ‘relevant’ delusions of persecution (r = .417, n = 55, p = .002) and no other delusions or hallucinations.
The moral cognitions involving ‘authority’ correlated positively with religious delusions (r = .480, n = 55, p = .000); relevant religious delusions (r = .509, n = 55, p = .000); command hallucinations (r = .310, n = 55, p = .021); and relevant command hallucinations (r = .323, n = 55, p = .016).
The moral cognition involving ‘purity-disgust’ was significantly positively correlated with relevant voices criticizing (r = .328, n = 55, p = .015) but no other delusions or hallucinations.
There was a tendency for correlations between symptoms and moral cognitions to be stronger where the symptom was judged ‘relevant’ to the violent act. Out of 11 cases where there was a significant correlation; in 8 cases the ‘relevant’ symptom had stronger correlations with moral cognitions, 1 case was tied, and in 2 cases symptoms that were present at the time of the act had stronger correlations than those that were judged by treating psychiatrists to be ‘relevant’ to the act. Using the binomial probability theorem [
70,
71] and assuming an equal probability for present or ‘relevant’ symptoms to have stronger correlations with moral cognitions the Binomial probability was
p = 0.043. This finding indicates that symptoms judged to be ‘relevant’ by the treating or admitting psychiatrists were more likely to have a stronger correlation with specific moral cognitions than those symptoms which were judged only to be present.
Hypothesis 4: Specific psychotic symptoms will be
relevant
for violence when mediated by specific moral cognitions and moral cognition may contribute to violence independently of psychotic symptoms.
Table
6 shows the results of mediation analysis with models derived as described above. We found evidence that specific moral cognitions mediated the relationship between the presence of specific psychotic symptoms and their ‘relevance’ for acts of violence.
Table 6
The mediating effect of moral cognition on delusions / hallucinations (X) and relevance for the violent act)
M is care-harm, X are delusions Y is whether the delusions or hallucinations were relevant to the violent act |
X = Delusions of guilt Y = Relevance | .999 | .000 | .867 | .767 | .967 | 9.900 | -1163.928 | 1183.730 | 3.128 | 1.854 | 6.690 | 3.699 | -575.590 | 582.988 |
X = Religious delusions Y = Relevance | .960 | .000 | .962 | .908 | 1.016 | .952 | .891 | 1.012 | .010 | -.0097 | .060 | .030 | -.048 | .108 |
X = Grandiose Y = Relevance | .949 | .000 | .839 | .762 | .915 | .835 | .755 | .914 | .004 | -.0212 | .048 | .015 | -.065 | .097 |
M is fairness-injustice, Y is whether the delusions or hallucinations were relevant to the violent act |
X = Persecutory delusions Y = Relevance | .930 | .000 | .953 | .846 | 1.062 | .917 | .807 | 1.027 | .035 | -.001 | .139 | .125 | .010 | .239 |
X = Somatic delusions Y = Relevance | .934 | .000 | .870 | .779 | .961 | .874 | .777 | .971 | -.004 | -.022 | .003 | -.008 | -.067 | .051 |
X = Delusions of mind reading Y = Relevance | .897 | .000 | .634 | .548 | .720 | .635 | .546 | .724 | -.001 | -.023 | .010 | -.002 | -.056 | .050 |
X = Somatic/tactile hallucinations Y = Relevance | .745 | .000 | .404 | .302 | .505 | .392 | .288 | .469 | .011 | .000 | .039 | .034 | -.031 | .110 |
M is loyalty-betrayal, Y is whether the delusions or hallucinations were relevant to the violent act |
X = Persecutory delusions Y = Relevance | .867 | .000 | .953 | .844 | 1.062 | .915 | .805 | 1.024 | .038 | .005 | .135 | .130 | .019 | .241 |
X = Delusions of doubles Y = Relevance | .919 | .000 | .911 | .804 | 1.019 | .916 | .806 | 1.026 | -.004 | -.038 | .005 | -.018 | -.105 | .067 |
M is authority, Y is whether delusions or hallucinations were relevant to the violent act |
X = Religious delusions Y = Relevance | .980 | .000 | .962 | .908 | 1.016 | .960 | .893 | 1.027 | .002 | -.0338 | .055 | .004 | -.068 | .077 |
X = Command hallucinations Y = Relevance | .961 | .000 | .868 | .798 | .938 | .892 | .814 | .970 | -.023 | -.0813 | .007 | -.053 | -.132 | .026 |
M is sanctity -degradation, Y is whether delusions or hallucinations were relevant to the violent act. |
X = Auditory hallucinations Y = Relevance | .898 | .000 | .863 | .783 | .943 | .857 | .773 | .940 | .006 | -.0088 | .035 | .020 | -.048 | .089 |
Religious delusions and grandiose delusions correlated with moral cognitions involving ‘care-harm’; however, there was no mediating relationship between ‘care-harm’ and the ‘relevance’ of these delusions to violence. Although delusions of guilt were not correlated with ‘care-harm’, it significantly contributed to the ‘relevance’ of delusions of guilt to acts of violence when controlling for their presence.
There was no mediating relationship between ‘fairness-injustice’, persecutory delusions and the ‘relevance’ of persecutory delusions to violence. However, ‘fairness-injustice’ made an independent contribution to the ‘relevance’ of persecutory delusions to acts of violence, when controlling for persecutory delusions.
Although somatic delusions and delusions of mind reading were correlated with ‘fairness-injustice’, there was no mediating relationship between ‘fairness-injustice’ and the relevance of these delusions to acts of violence.
The relationship between somatic or tactile hallucinations and their relevance for violence was completely mediated by moral cognitions regarding ‘fairness-injustice’.
The relationship between persecutory delusions and their ‘relevance’ to violence was completely mediated by ‘loyalty-betrayal’, with ‘loyalty-betrayal’ also making an independent contribution to the model. Finally, although religious delusions and command hallucinations were correlated with ‘authority’, their ‘relevance’ to acts of violence was not mediated by ‘authority’.
Hypothesis 5: Specific psychotic symptoms will be associated with seriousness and forms of violence when mediated by specific moral cognitions and moral cognitions may contribute to seriousness and forms of violence independently of psychotic symptoms.
We found evidence that specific moral cognitions mediated the relationship between psychotic symptoms and the seriousness and form of violence (Table
7).
Table 7
The mediating effect of moral cognition on homicide, seriousness of violence and reactive-instrumental violence
M is loyalty-betrayal, Y is homicide |
X = Persecutory delusions | .320 | .000 | -.260 | -.534 | .013 | -.498 | -.860 | -.136 | .163 | .015 | .456 | .555 | .185 | .926 |
X = Delusions involving doubles | .215 | .007 | .438 | .0188 | .858 | .384 | -.042 | .811 | .070 | -.004 | .239 | .292 | .008 | .576 |
M is loyalty-betrayal, Y is seriousness of violence |
X = Persecutory delusions | .140 | .019 | -.140 | -.395 | .113 | -.240 | -.493 | .012 | .099 | .013 | .265 | .339 | .083 | .595 |
X = Delusions involving doubles | .109 | .048 | .268 | -.054 | .592 | .212 | -.109 | .534 | .056 | -.001 | .185 | .235 | -.017 | .488 |
M is fairness-injustice, Y is Cornell’s instrumental-reactive aggression |
X = Persecutory delusions | .259 | .000 | -.137 | -.282 | .008 | -.062 | -.199 | .074 | -.074 | -.172 | -.013 | -.263 | -.406 | -.121 |
X = Somatic delusions | .253 | .000 | -.075 | -.32 | .177 | .075 | -.157 | .308 | -.151 | -.255 | -.068 | -.297 | -.441 | -.153 |
X = Delusions of mind reading | .250 | .000 | -.043 | -.302 | .215 | .052 | -.179 | .284 | -.096 | -.268 | .063 | -.029 | -.429 | -.149 |
X = Somatic/tactile hallucinations | .251 | .000 | -.042 | -.289 | .205 | .055 | -.165 | .277 | -.098 | -.239 | .019 | -.290 | -.430 | -.150 |
M is loyalty-betrayal, Y is Cornell’s instrumental-reactive aggression |
X = Persecutory delusions | .249 | .000 | -.137 | -.282 | .008 | -.063 | -.201 | .074 | -.073 | -.170 | -.015 | -.250 | -.389 | -.110 |
M is authority, Y is Cornell’s instrumental-reactive aggression |
X = Religious delusions | .096 | .071 | .041 | -.098 | .180 | -.068 | -.234 | .097 | .109 | .105 | .243 | .205 | .024 | .386 |
X = Command hallucinations | .120 | .036 | .164 | .020 | .308 | .115 | -.045 | .276 | .048 | -.018 | .150 | .186 | -.054 | .272 |
Expert rated ‘loyalty-betrayal’ was the only moral cognition which was associated with homicide. Delusions of persecution were the only psychotic symptoms which correlated with ‘loyalty-betrayal’. The relationship between persecutory delusions and homicide was completely mediated by ‘loyalty-betrayal’. Although the overall correlation between persecutory delusions and homicide was negative (inverse), the mediation effect of ‘loyalty-betrayal’ revealed a positive relationship between persecutory delusions and homicide, provided ‘loyalty-betrayal’ was judged to be present by expert clinicians blind to the rating of delusions by treating clinicians. Within the mediation model, persecutory delusions that were not associated with ‘loyalty-betrayal’ were negatively associated with homicide, but persecutory delusions which were positively associated with ‘loyalty-betrayal’ were positively associated with homicide. ‘Loyalty-betrayal’ also had a direct effect on homicide when controlling for persecutory delusions. ‘Loyalty-betrayal’ did not mediate the relationship between delusions involving doubles and homicide, however, both made a significant contribution to the model.
Expert rated ‘loyalty-betrayal’ was also the only moral cognition that was associated with the seriousness of violence. The relationship between persecutory delusions and seriousness of violence was completely mediated and reversed by ‘loyalty-betrayal’. Similarly, for homicide, persecutory delusions that were not associated with ‘loyalty-betrayal’ were negatively associated with seriousness of violence, but persecutory delusions which were positively associated with loyalty-betrayal were also positively associated with seriousness of violence. ‘Loyalty-betrayal’ also had a direct effect on seriousness of violence when controlling for persecutory delusions.
Expert rated ‘fairness-injustice’ was negatively associated with Cornell’s instrumental-reactive aggression (i.e. positively associated with reactive violence). ‘Fairness-injustice’ completely mediated the relationship between persecutory delusions and instrumental violence, and partially mediated the relationship between somatic delusions and instrumental violence, making an independent contribution to the model in both cases.
Although ‘fairness-injustice’ was positively associated with somatic delusions and delusions of mind reading, it did not mediate the relationship between these psychotic phenomena and instrumental violence.
‘Loyalty-betrayal’ was also negatively associated with Cornell’s instrumental-reactive aggression scheme (i.e. positively associated with reactive violence). ‘Loyalty-betrayal’ completely mediated the relationship between persecutory delusions and instrumental violence, whilst making an independent contribution to the model.
Religious delusions and command hallucinations were both positively associated with moral cognitions involving ‘authority’. ‘Authority’ completely mediated the relationship between religious delusions and Cornell’s reactive-instrumental violence scheme, making an independent contribution to the model. In other words, religious delusions were positively associated with instrumental acts of violence when mediated through ‘authority’.