Aggression-related Behaviors Research Articles

Traumatic Brain Injury and Related Antisocial Behavioral Outcomes: A Systematic Review.

Background and Objectives: Higher level of aggression and antisocial behavior have been found in the period following head trauma. These changes are attributable to specific brain alterations that generally involved frontal lobe, insula and limbic system. A descriptive review was conducted on the specificity of aggressive behavior in relation to traumatic brain injury by evaluating numerous variables, focusing on age at the time of trauma and neuroimaging studies. Materials and Methods: We searched on PubMed and the Web of Science databases to screen references of included studies and review articles for additional citations. From an initial 738 publications, only 27 met the search criteria of describing the relationship between aggression, brain alterations and traumatic brain injury. Results: These findings showed that traumatic brain injury (TBI) is related to changes in behavior, personality and mood. Conclusions: The development of aggressive and criminal behavior is associated with multiple factors, including the etiology of injury, environmental, psychosocial and personality factors and age at the time of trauma.

Effects of Positive Fighting Experience and Its Subsequent Deprivation on the Expression Profile of Mouse Hippocampal Genes Associated with Neurogenesis.

The hippocampus is known as the brain region implicated in visuospatial processes and processes associated with learning and short- and long-term memory. An important functional characteristic of the hippocampus is lifelong neurogenesis. A decrease or increase in adult hippocampal neurogenesis is associated with a wide range of neurological diseases. We have previously shown that in adult male mice with a chronic positive fighting experience in daily agonistic interactions, there is an increase in the proliferation of progenitor neurons and the production of young neurons in the dentate gyrus (in hippocampus), and these neurogenesis parameters remain modified during 2 weeks of deprivation of further fights. The aim of the present work was to identify hippocampal genes associated with neurogenesis and involved in the formation of behavioral features in mice with the chronic experience of wins in aggressive confrontations, as well as during the subsequent 2-week deprivation of agonistic interactions. Hippocampal gene expression profiles were compared among three groups of adult male mice: chronically winning for 20 days in the agonistic interactions, chronically victorious for 20 days followed by the 2-week deprivation of fights, and intact (control) mice. Neurogenesis-associated genes were identified whose transcription levels changed during the social confrontations and in the subsequent period of deprivation of fights. In the experimental males, some of these genes are associated with behavioral traits, including abnormal aggression-related behavior, an abnormal anxiety-related response, and others. Two genes encoding transcription factors (Nr1d1 and Fmr1) were likely to contribute the most to the between-group differences. It can be concluded that the chronic experience of wins in agonistic interactions alters hippocampal levels of transcription of multiple genes in adult male mice. The transcriptome changes get reversed only partially after the 2-week period of deprivation of fights. The identified differentially expressed genes associated with neurogenesis and involved in the control of a behavior/neurological phenotype can be used in further studies to identify targets for therapeutic correction of the neurological disturbances that develop in winners under the conditions of chronic social confrontations.

Callous unemotional traits mediate the presence of challenging behaviors in adults with autism spectrum disorder and intellectual disability

Background: Callous-unemotional traits (CUT) are an antisocial personality trait, which can be present in people with autism spectrum disorder (ASD), especially in relation to difficulties in empathy. These traits are related to challenging behaviors, such as aggressive behavior, which may occur in people with ASD. Method: This study aimed to expand the understanding of the role of CUT in adults with ASD and intellectual disability (ID). Eighty-three adults with a diagnosis of ASD and ID participated in the study. Results: Mediation analyses found that CUT indirectly mediated the relationship between ASD symptomatology and the frequency of self-injuries and stereotypies, but not aggression. Conclusions: It is considered that CUT may have a protective effect on the presence of individual challenging behaviors in adults with ASD and ID. The apparent relationship between CUT and executive functioning was discussed. CUT traits may be considered as a variable to contemplate in relation to interventions in challenging behaviors in the ASD population, especially in those individuals who show aggression-related behaviors and who have a higher executive level.

Lower cerebello-cortical functional connectivity in veterans with reactive aggression symptoms: A pilot study

A significant number of veterans experience irritability and aggression symptoms as a result of being exposed to extremely stressful and life-threatening situations. In addition to the well-established involvement of the brain's cortico-subcortical circuit in aggression-related behaviours, a role of the deep cerebellar nuclei (DCN) in reactive aggression has been suggested. In the present study, seed-based resting-state functional connectivity between the DCN and cortico-subcortical areas was explored in veterans with and without reactive aggression symptoms. Nineteen male veterans with reactive aggression symptoms and twenty-two control veterans without reactive aggression symptoms underwent 3T resting-state functional MRI scans. Region-of-interest (ROI) analyses that included the amygdala, hypothalamus and periaqueductal grey as ROIs did not yield significant group-related differences in resting-state functional connectivity with the DCN. However, exploratory whole-brain analysis showed that veterans with reactive aggression symptoms exhibited lower functional connectivity between the DCN and the orbitofrontal cortex compared to control veterans. Our findings provide preliminary evidence for the possible involvement of a cerebello-prefrontal pathway in reactive aggression in male veterans.

Immunohistochemical Distribution of Serotonin Transporter (SERT) in the Optic Lobe of the Honeybee, Apis mellifera.

Simple SummarySerotonin is ubiquitously expressed in vertebrates and invertebrates, where it regulates specific behavioural patterns. Though the specific effects of serotonin release in the optic lobe are not entirely known, increasing evidence associates the serotonergic system with optic lobe-mediated behaviours. In this study, the localization of serotonin transporter (SERT) was immunohistochemically analysed in the optic lobes of moderate, docile and aggressive worker honeybees. SERT-immunoreactive fibres were stratified in the optic lobe and distributed in the three visual neuropils: lamina, medulla and lobula. Interestingly, SERT immunoreactivity was inversely related to aggressive behaviour. The present study indicates that low levels of serotonin in the optic lobe are associated with aggressive behaviour.Visual information is processed in the optic lobes, which consist of three retinotopic neuropils. These are the lamina, the medulla and the lobula. Biogenic amines play a crucial role in the control of insect responsiveness, and serotonin is clearly related to aggressiveness in invertebrates. Previous studies suggest that serotonin modulates aggression-related behaviours, possibly via alterations in optic lobe activity. The aim of this investigation was to immunohistochemically localize the distribution of serotonin transporter (SERT) in the optic lobe of moderate, docile and aggressive worker honeybees. SERT-immunoreactive fibres showed a wide distribution in the lamina, medulla and lobula; interestingly, the highest percentage of SERT immunoreactivity was observed across all the visual neuropils of the docile group. Although future research is needed to determine the relationship between the distribution of serotonin fibres in the honeybee brain and aggressive behaviours, our immunohistochemical study provides an anatomical basis supporting the role of serotonin in aggressive behaviour in the honeybee.

Cognitive enrichment in a social setting: assessing the use of a novel food maze in sanctuary-housed chimpanzees

Foraging devices are effective enrichment tools for non-human primates, as they provide both cognitive and manipulative stimulation that may enhance these animals’ welfare. We assessed the behavioral effects of a novel tool-based enrichment on 14 chimpanzees (Pan troglodytes) housed at Fundació Mona (Girona, Spain). The device consisted of a vertical maze filled with food rewards, which chimpanzees could extract by using tools. We conducted behavioral observations in two conditions over an approximately 2.5-month period: when the food maze was loaded (12 enrichment days), and when it was empty (12 baseline days). Data were collected using 2-min scan sampling and untimed-event focal sampling during two daily sessions of 80 min each. We expected that the chimpanzees’ interest in the enrichment would decrease over time, but that its use would be linked to an increase in the occurrence of species-typical behaviors, a reduction in negative indicators of welfare, and changes in social behaviors. We found that participation widely varied among subjects, being higher in females and decreasing through time. Furthermore, participation was linked to an increase in tool use and a decrease in inactivity, but also to an increase in aggression-related behaviors. In contrast, participation had no effect on the occurrence of abnormal behaviors, social proximity or affiliation-related behaviors. Finally, we detected an increase in self-directed behaviors only when subjects actively interacted with the device. We conclude that, in future studies, these types of devices should be evaluated for longer periods of time and more attention should be paid to individuals’ preferences and abilities.

P43. Association Between Thalamic Volume and Angry Rumination in Adolescent Cannabis Users

Cannabis (CB) use has been associated with alterations in brain structure and function as well as behavioral challenges including aggression. However, displaced aggression, defined as the tendency to shift affective, cognitive, and behavioral responses to provocation towards undeserving others has not been widely explored. In this study, we assessed the relationship between displaced aggression and thalamic volume, which has previously been associated with anger and aggression related behaviors.

Predation Stress Causes Excessive Aggression in Female Mice with Partial Genetic Inactivation of Tryptophan Hydroxylase-2: Evidence for Altered Myelination-Related Processes.

The interaction between brain serotonin (5-HT) deficiency and environmental adversity may predispose females to excessive aggression. Specifically, complete inactivation of the gene encoding tryptophan hydroxylase-2 (Tph2) results in the absence of neuronal 5-HT synthesis and excessive aggressiveness in both male and female null mutant (Tph2−/−) mice. In heterozygous male mice (Tph2+/−), there is a moderate reduction in brain 5-HT levels, and when they are exposed to stress, they exhibit increased aggression. Here, we exposed female Tph2+/− mice to a five-day rat predation stress paradigm and assessed their emotionality and social interaction/aggression-like behaviors. Tph2+/− females exhibited excessive aggression and increased dominant behavior. Stressed mutants displayed altered gene expression of the 5-HT receptors Htr1a and Htr2a, glycogen synthase kinase-3 β (GSK-3β), and c-fos as well as myelination-related transcripts in the prefrontal cortex: myelin basic protein (Mbp), proteolipid protein 1 (Plp1), myelin-associated glycoprotein (Mag), and myelin oligodendrocyte glycoprotein (Mog). The expression of the plasticity markers synaptophysin (Syp) and cAMP response element binding protein (Creb), but not AMPA receptor subunit A2 (GluA2), were affected by genotype. Moreover, in a separate experiment, naïve female Tph2+/− mice showed signs of enhanced stress resilience in the modified swim test with repeated swimming sessions. Taken together, the combination of a moderate reduction in brain 5-HT with environmental challenges results in behavioral changes in female mice that resemble the aggression-related behavior and resilience seen in stressed male mutants; additionally, the combination is comparable to the phenotype of null mutants lacking neuronal 5-HT. Changes in myelination-associated processes are suspected to underpin the molecular mechanisms leading to aggressive behavior.

Artificial Termite-Fishing Tasks as Enrichment for Sanctuary-Housed Chimpanzees: Behavioral Effects and Impact on Welfare.

Simple SummaryThe welfare of captive animals is nowadays a topic of major concern. In order to express their natural behavioral repertoires, however, animals require complex environments and stimuli which are difficult to reproduce in captivity. To overcome this, environmental enrichment is considered one of the most successful tools to increase behavioral opportunities and enhance animal welfare. In this study, we explored whether providing an artificial termite-fishing task, and whether participation in this task, predicted changes in the solitary and social behavior of sanctuary-housed chimpanzees (Pan troglodytes). We compared chimpanzee behavior when the enrichment was presented to different periods without enrichment. We found that the presence of the enrichment predicted an increase in tool use and feeding behavior and a decrease in inactivity, especially for those chimpanzees with higher participation. However, we did not detect significant changes in abnormal or self-directed behaviors. Furthermore, we found no variation in affiliation- or aggression-related behaviors, but social proximity increased in chimpanzees that participated more. Our results support previous studies demonstrating that artificial termite-fishing promotes species-typical behaviors in captive chimpanzees with no major effects on social activities.Artificial termite-fishing tasks are a common enrichment for captive great apes, promoting species-typical behaviors. Nonetheless, whether these activities are linked to changes in other behaviors and whether these changes persist over time has seldom been investigated. We assessed whether the use of an artificial termite-fishing task was linked to changes in the solitary behavior and social dynamics in two groups of sanctuary-housed chimpanzees (Pan troglodytes). Specifically, we compared chimpanzee behavior during eight enrichment sessions distributed over a two-month period, with similar periods before and after the introduction of the enrichment. Data were collected from combined interval and continuous sampling methods and were analyzed using generalized linear mixed models. We found that participation increased across sessions and that both enrichment and participation predicted an increase in tool use and feeding and a decrease in inactivity, which were all maintained throughout the sessions. Furthermore, participation was positively associated with social proximity, revealing a gathering effect of the task. However, neither enrichment nor participation were linked to changes in abnormal, self-directed, affiliation-related or aggression-related behaviors. Overall, our results support the hypothesis that artificial termite-fishing is a suitable enrichment for captive chimpanzees, maintaining the subjects’ interest and promoting species-typical behaviors, with no negative effects on social activities.

Neuroendocrine and Cardiovascular Activation During Aggressive Reactivity in Dogs.

Our aim was to investigate cardiovascular activation by measuring changes in facial and body surface temperature using infrared thermography, and neuroendocrine activation using salivary cortisol (CORT) and serotonin concentration (SER) in dogs exhibiting aggressive reactivity in real time. Based on two factors, owner-reported past aggressive behaviors, and detailed behavioral observations collected during a Socially Acceptable Behavior test consisting of 16 subtests and, each individual was categorized as aggressive or non-aggressive. CORT and SER showed no difference in neuroendocrine activity between dogs, but aggressive dogs with higher levels of aggression were found to have lower SER. Aggressive dogs also had an increase in facial temperature from pre-test values. The discovery of a correlation between tail wagging and left tail wagging with aggression level and aggression-related behaviors in aggressive dogs is further evidence of the right hemisphere specialization for aggression previously reported in the literature. This study provides the first evidence that both cardiovascular and neuroendocrine systems are activated during an active act of aggression in dogs.

Effect of family relations and school environment on aggressive behavior of school age students

Background: Family and school conditions have been reliably connected to aggression issues in adolescence. Aim: Assessing effect of family relations and school environment on aggressive behavior of school age students, exploring the difference between adolescence aggressive behavior in relation to teaching environment and family relation. Design: A descriptive, cross-sectional design was utilized. Setting: The study was conducted at two randomly selected preparatory governmental schools affiliated to Al-Sayeda Zeinab educational directorate, Cairo, Egypt. Sample: A purposive sample of 180 adolescents in selected preparatory schools was included in the study. Tools: Five tools were used, 1) Socio-demographic data sheet for students, 2) Socio-demographic data sheet for parents, 3) Aggressive Behavior Scale, 4) Brief Family Relationship Scale and 5) School Climate Scale. Results: Showed that there were “statistical significant differences” between father and mother educational characteristics and methods of home punishment. Also, there was a significant statistical relationship between family relations and aggressive behavior of children. Conclusion: A significant statistical relationship between family relations and aggressive behavior of children. Also, a significant statistical relationship was found between school environment and aggressive behavior of children. Also, a significant statistical relationship was revealed between aggressive behavior of children and socio-demographic characteristics of their parents. Recommendations: Psycho-educational programs about impulsivity, aggression, family relations will be important to increase students and parents’ awareness about behavioral competencies and challenges.

Appeasing Pheromones for the Management of Stress and Aggression during Conservation of Wild Canids: Could the Solution Be Right under Our Nose?

Simple SummaryMany canid species are declining globally. It is important to conserve these species that often serve as important predators within ecosystems. Continued human expansion and the resulting habitat fragmentation necessitate conservation interventions, such as translocation, artificial pack formation, and captive breeding programs. However, chronic stress often occurs during these actions, and can result in aggression, and the physiological suppression of immunity and reproduction. Limited options are currently available for stress and aggression management in wild canids. Pheromones provide a promising natural alternative for stress management; an appeasing pheromone has been identified for multiple domestic species and may reduce stress and aggression behaviours. Many pheromones are species-specific, and the appeasing pheromone has been found to have slight compositional changes across species. In this review, the benefits of a dog appeasing pheromone and the need to investigate species-specific derivatives to produce more pronounced and beneficial behavioural and physiological modulation in target species as a conservation tool are examined.Thirty-six species of canid exist globally, two are classified as critically endangered, three as endangered, and five as near threatened. Human expansion and the coinciding habitat fragmentation necessitate conservation interventions to mitigate concurrent population deterioration. The current conservation management of wild canids includes animal translocation and artificial pack formation. These actions often cause chronic stress, leading to increased aggression and the suppression of the immune and reproductive systems. Castration and pharmaceutical treatments are currently used to reduce stress and aggression in domestic and captive canids. The undesirable side effects make such treatments inadvisable during conservation management of wild canids. Pheromones are naturally occurring chemical messages that modulate behaviour between conspecifics; as such, they offer a natural alternative for behaviour modification. Animals are able to distinguish between pheromones of closely related species through small compositional differences but are more likely to have greater responses to pheromones from individuals of the same species. Appeasing pheromones have been found to reduce stress- and aggression-related behaviours in domestic species, including dogs. Preliminary evidence suggests that dog appeasing pheromones (DAP) may be effective in wild canids. However, the identification and testing of species-specific derivatives could produce more pronounced and beneficial behavioural and physiological changes in target species. In turn, this could provide a valuable tool to improve the conservation management of many endangered wild canids.

Quantitative standardization of resident mouse behavior for studies of aggression and social defeat.

Territorial reactive aggression in mice is used to study the biology of aggression-related behavior and is also a critical component of procedures used to study mood disorders, such as chronic social defeat stress. However, quantifying mouse aggression in a systematic, representative, and easily adoptable way that allows direct comparison between cohorts within or between studies remains a challenge. Here, we propose a structural equation modeling approach to quantify aggression observed during the resident-intruder procedure. Using data for 658 sexually experienced CD-1 male mice generated by three research groups across three institutions over a 10-year period, we developed a higher-order confirmatory factor model wherein the combined contributions of latency to the first attack, number of attack bouts, and average attack duration on each trial day (easily observable metrics that require no specialized equipment) are used to quantify individual differences in aggression. We call our final model the Mouse Aggression Detector (MAD) model. Correlation analyses between MAD model factors estimated from multiple large datasets demonstrate generalizability of this measurement approach, and we further establish the stability of aggression scores across time within cohorts and demonstrate the utility of MAD for selecting aggressors which will generate a susceptible phenotype in social defeat experiments. Thus, this novel aggression scoring technique offers a systematic, high-throughput approach for aggressor selection in chronic social defeat stress studies and a more consistent and accurate study of mouse aggression itself.

Moral Reasoning about Aggressive Behavior in Relation to Type of Aggression, Age and Gender in South Korean Pupils.

Studies of moral reasoning in relation to aggressive behaviors have paid limited attention to different types of aggression, and have mainly been conducted in Western societies. We describe findings from a study of 157 children, aged 6 or 11 years, from two schools in South Korea. Using a cartoon scenario methodology, we assessed moral reasoning about eight types of aggression: verbal, physical individual, physical group, social exclusion, rumor spreading, breaking one’s belongings, sending a nasty text via mobile phone, and sending a nasty message/email via computer. Four aspects of moral reasoning were assessed: moral judgment, harmfulness, reason for judgment, and causal responsibility. Many significant differences by type of aggression were found, especially for social exclusion (seen as less wrong and harmful, and more the victim’s responsibility), physical group aggression (seen as more wrong or harmful, and a matter of fairness, especially in older children and boys), and cyber aggression (seen more as the aggressor’s responsibility). Older children gave more reasons based on welfare, and fewer “don’t know” responses for reasons and attributions. Gender differences were relatively few, but girls did make more use of welfare in the moral reasoning domain. Findings are discussed in relation to previous research and the cultural context in South Korea.

The Gender-Related Impact of a Violence Management Training Program on Medical School Students-Preliminary Results.

Phenomenon: Patient aggression directed toward medical personnel, including medical school students during their internships, is an increasingly important issue. To minimize this phenomenon, violence management training programs were carried out. Approach: To assess the efficacy of a violence management training program among medical school students and evaluate changes in the perception of aggressive behavior in relation to the participants’ sense of self-efficacy and self-confidence by sex. A quasi-experimental examination of medical school students was performed before and after completion of a training program. Two hundred seventy-six students, including students of medicine, nursing, emergency medical services, and physiotherapy, participated in the study. Three standardized questionnaires were used: The Perception of Aggression Scale (POAS), the Hope for Success Questionnaire (HSQ), and the General Self -Efficacy Scale (GSES). Findings: The training program had a positive impact on the sense of self-efficacy in both men and women. However, the perception of aggressive behavior changed only in women and the impact of such intervention was higher for women. Further studies should look at the long-term outcomes.

Rage Against the Machine: Advancing the study of aggression ethology via machine learning.

Aggression, comorbid with neuropsychiatric disorders, exhibits with diverse clinical presentations and places a significant burden on patients, caregivers, and society. This diversity is observed because aggression is a complex behavior that can be ethologically demarcated as either appetitive (rewarding) or reactive (defensive), each with its own behavioral characteristics, functionality, and neural basis that may transition from adaptive to maladaptive depending on genetic and environmental factors. There has been a recent surge in the development of preclinical animal models for studying appetitive aggression-related behaviors and identifying the neural mechanisms guiding their progression and expression. However, adoption of these procedures is often impeded by the arduous task of manually scoring complex social interactions. Manual observations are generally susceptible to observer drift, long analysis times, and poor inter-rater reliability, and are further incompatible with the sampling frequencies required of modern neuroscience methods. In this review, we discuss recent advances in the preclinical study of appetitive aggression in mice, paired with our perspective on the potential for machine learning techniques in producing automated, robust scoring of aggressive social behavior. We discuss critical considerations for implementing valid computer classifications within behavioral pharmacological studies. Open-source automated classification platforms can match or exceed the performance of human observers while removing the confounds of observer drift, bias, and inter-rater reliability. Furthermore, unsupervised approaches can identify previously uncharacterized aggression-related behavioral repertoires in model species. Advances in open-source computational approaches hold promise for overcoming current manual annotation caveats while also introducing and generalizing computational neuroethology to the greater behavioral neuroscience community. We propose that currently available open-source approaches are sufficient for overcoming the main limitations preventing wide adoption of machine learning within the context of preclinical aggression behavioral research.

Evaluation of the relationship between MAOA-uVNTR gene polymorphism and impulsivity, anger, temperament and personality traits in healthy male subjects

Aim: Serotonergic activity in the central nervous system negatively correlates with personality traits associated with aggression, impulsivity and anger. MAOA is involved in the catabolism of serotonin and norepinephrine, so the gene encoding MAOA is a candidate gene for aggression-related behavior. It is thought that MAOA genetic variants affect the MAOA activity at different degrees, leading to behavioral changes as a result of a decrease in enzyme activity. The aim of this study is investigating the possible relationship between the MAOA-uVNTR polymorphism genotypes and aggression, anger, impulsivity, temperament-character traits in healthy male subjects. Materials and Methods: 101 Turkish healthy male subjects were included in the study. The participants were given scales to evaluate impulsivity, temperament and character traits, anger and aggression levels. MAOA-uVNTR polymorphism was examined with a sample taken from peripheral blood.Results: A total of 101 people, 33.6% had low-activity allele and 66.4% had high-activity allele of MAOA gene. There was no significant relationship between the temperament-character traits of the participants and MAOA-uVNTR polymorphism. Impulsivity scales were higher in the low-activity allele group, which was statistically significant in terms of motor impulsivity (p = 0.007), non-planning impulsivity (p = 0.031) and total scores (p = 0.029). Conclusion: The low-activity allele of MAOA gene may be a marker for impulsivity. This requires both repetitive studies with healthy controls in the Turkish population and studies in different cultures.

The perceptions of inpatients with schizophrenia about aggression: a qualitative study

Objective: Patients with schizophrenia may be at increased risk of aggressive behavior in relation to factors such as symptoms and severity of the disease. In this study, it is aimed to explore the thoughts and experiences of aggression in schizophrenia patients using a semi-structured interview questionnaire. Methods: Semi-structured individual interviews were conducted with 26 patients who had been hospitalized with a diagnosis of schizophrenia in Elazig Mental Health and Diseases Hospital. Interviews were recorded with voice recording and then transcribed. Content analysis was used in data analysis. Results: As a result of the analysis of the data obtained from the interviews, four themes were identified: aggressive behavior, feelings, consequences, suggestions. It was determined that consists of subthemes as ‘violence’, ‘mental illness’ for aggressive behavior theme; ‘regret’ for feelings theme; ‘sent to prison, a closed service’, ‘death, wounding’ and ‘loss of hope’ for consequences theme; ‘treatment and rehabilitation’, ‘communication’, ‘spirit’ and ‘education’, ‘awareness’ for suggestions theme. Conclusions: This study includes the physical, psychological and social reasons for the aggressive behaviors experienced in patients with schizophrenia, possible consequences and suggestions for preventing the occurrence of behavior. It is estimated that these results will enlighten on providing health care professionals and caregivers with the necessary support in sharing feelings in the management of the patient's aggressive behavior.

Personality Patterns in Familiar and Delinquency Violence in Mexican Men

The objective of this study was to examine personality patterns of aggressive and violent behaviors in the Minnesota Multiphasic Personality Inventory (MMPI-2) scales data obtained from homicide and domestic violence offenders. A group of homicide and domestic violence offenders were administered the test to identify differences and causes. Method 140 subjects participated in this study. We divided them into two groups of 70 incarcerated offenders each based on the cause of their arrest: homicide and domestic violence. Inmates were sampled by non-probability quota sampling, and voluntarily completed the Inventory after giving informed consent. Results: By applying the parametric Student's t-test to the scales and using Cohen's d, the effect size of identified differences was obtained. High scores in some scales suggesting differences in expression of aggression between groups were observed. Homicide offenders expressed more openly emotions of aggression, hostility, and anger, while domestic violence perpetrators tend to deny any such factors in their behavior. Both groups showed emotional deviation associated with their offenses. Conclusions: The MMPI-2 has been proved to detect behavior patterns of offenders and their reluctance to readapt to civil society. An interesting matter can be highlighted: Given the conditions in Mexican correctional facilities, currently offenders overall are not motivated enough to reintegrate into social life, having expressed reactions of aggression-related behaviors.

La personalidad premórbida como factor de riesgo en la aparición de síntomas psicológicos y conductuales de la demencia: revisión sistemática

The aetiology of behavioural and psychological symptoms of dementia (BPSD) is defined by a diversity of factors, and recent studies suggest that premorbid personality could be a risk factor for BPSD. This study aimed to review studies on the relationship between premorbid personality and BPSD.Studies were identified using PsycInfo, MedLine, and PubMed. The searches combined terms for premorbid personality, dementia and BPSD. Ten studies have been included in this review.Eight out of ten studies show a relationship between premorbid personality and BPSD. Neuroticism is associated with behavioural disturbances and anxiety. Extraversion is associated with wandering. Low agreeableness is associated with affective disturbance and aggression-related behaviours and high agreeableness is associated with wandering. The studies found no congruent results for openness and conscientiousness.In conclusion, premorbid personality may increase the risk of developing BPSD during the course of the disease. Even so, the relationship between personality and BPSD is complex due to multifactorial aetiology.