Who's flying the plane: serotonin levels, aggression and free will

Aggression, Aggression-Related Psychopathologies and Their Models

Neural mechanisms of aggression and violence are often studied in the laboratory by means of animal models. A multitude of such models were developed over the last decades, which, however, were rarely if ever compared systematically from a psychopathological perspective. By overviewing the main models, I show here that the classical ones exploited the natural tendency of animals to defend their territory, to fight for social rank, to defend themselves from imminent dangers and to defend their pups. All these forms of aggression are functional and adaptive; consequently, not necessarily appropriate for modeling non-natural states, e.g., aggression-related psychopathologies. A number of more psychopathology-oriented models were also developed over the last two decades, which were based on the etiological factors of aggression-related mental disorders. When animals were exposed to such factors, their aggressiveness suffered durable changes, which were deviant in the meaning that they broke the evolutionarily conserved rules that minimize the dangers associated with aggression. Changes in aggression were associated with a series of dysfunctions that affected other domains of functioning, like with aggression-related disorders where aggression is just one of the symptoms. The comparative overview of such models suggests that while the approach still suffers from a series of deficits, they hold the important potential of extending our knowledge on aggression control over the pathological domain of this behavior.

The Youngest, the Heaviest and/or the Darkest? Selection Potentialities and Determinants of Leadership in Canarian Dromedary Camels

Simple Summary

Genetic selection of camels for behavioral traits is not an extended practice in livestock scenarios. Given the existence of pleiotropic genes that influence two or more seemingly unrelated phenotypic traits, here we studied the sociodemographic, zoometric and phaneroptical characteristics potentially determining the intraherd leadership role in Canarian camels. This local endangered breed is mainly reared in same-sex groups because of biased morphostructural preferences, that is, tourism/leisure and milk production for males and females, respectively. The attribute most influencing leadership role was sexual status, as gelded animals more frequently initiated group movements. Furthermore, younger camels were mainly endorsed as group leaders, a condition that could be ascribed to their recognized fluid intelligence and need for constant social and environmental interaction. Referring to zoometrics and phaneroptics, the heaviest and darkest-coated dromedaries were significantly more prone to reaching higher positions in the leadership hierarchy. The presence of white-haired zones in the extremities, head and neck as well as iris depigmentation had non-negligible influence on this type of social organization. This information is valuable for application both in refining animal handling procedures and in genetic selection of animals for their social behavior.

Abstract

Several idiosyncratic and genetically correlated traits are known to extensively influence leadership in both domestic and wild species. For minor livestock such as camels, however, this type of behavior remains loosely defined and approached only for sex-mixed herds. The interest in knowing those animal-dependent variables that make an individual more likely to emerge as a leader in a single-sex camel herd has its basis in the sex-separated breeding of Canarian dromedary camels for utilitarian purposes. By means of an ordinal logistic regression, it was found that younger, gelded animals may perform better when eliciting the joining of mates, assuming that they were castrated just before reaching sexual maturity and once they were initiated in the pertinent domestication protocol for their lifetime functionality. The higher the body weight, the significantly (p < 0.05) higher the score in the hierarchical rank when leading group movements, although this relationship appeared to be inverse for the other considered zoometric indexes. Camels with darker and substantially depigmented coats were also significantly (p < 0.05) found to be the main initiators. Routine intraherd management and leisure tourism will be thus improved in efficiency and security through the identification and selection of the best leader camels.

Conduct disorder and somatic health in children: a nationwide genetically sensitive study

BACKGROUND

Conduct disorder (CD), a serious behavioral and emotional disorder in childhood and adolescence, characterized by disruptive behavior and breaking societal rules. Studies have explored the overlap of CD with neurodevelopmental problems (NDP). The somatic health of children with NDP has been investigated; however, the prevalence of these problems in children with CD has not been sufficiently studied. Holistic assessment of children with CD is required for establishing effective treatment strategies.

AIMS

(1) Define the prevalence of selected neurological problems (migraine and epilepsy) and gastrointestinal problems (celiac disease, lactose intolerance, diarrhea, and constipation) in a population of twins aged 9 or 12; (2) Compare the prevalence of somatic problems in three subpopulations: (a) children without CD or NDP, (b) children with CD, and (c) children with both CD and NDP; (3) Select twin pairs where at least one child screened positive for CD but not NDP (proband) and map both children's neurological and gastrointestinal problems.

METHOD

Telephone interviews with parents of 20,302 twins in a cross-sectional, nationwide, ongoing study. According to their scores on the Autism-Tics, AD/HD, and Comorbidities inventory, screen-positive children were selected and divided into two groups: (1) children with CD Only, (2) children with CD and at least one NDP.

RESULTS

Children with CD had an increased prevalence of each neurological and gastrointestinal problem (except celiac disease), and the prevalence of somatic problems was further increased among children with comorbid CD and NDP. The presence of CD (without NDP) increased the odds of constipation for girls and the odds of epilepsy for boys. Girls with CD generally had more coexisting gastrointestinal problems than boys with CD. Female co-twins of probands with CD were strongly affected by gastrointestinal problems. Concordance analyses suggested genetic background factors in neurological and gastrointestinal problems, but no common etiology with CD could be concluded.

CONCLUSION

Co-occurring NDP could explain most of the increased prevalence of somatic problems in CD. Our results raise a new perspective on CD in children and adolescents; their CD seems to be linked to a number of other health problems, ranging from neurodevelopmental and psychiatric disorders to somatic complaints.

Blame and its consequences for healthcare professionals: response to Tigard

Tigard (2019) suggests that the medical community would benefit from continuing to promote notions of individual responsibility and blame in healthcare settings. In particular, he contends that blame will promote systematic improvement, both on the individual and institutional levels, by increasing the likelihood that the blameworthy party will 'own up' to his or her mistake and apologise. While we agree that communicating regret and offering a genuine apology are critical steps to take when addressing patient harm, the idea that medical professionals should continue to 'take the blame' for medical errors flies in the face of existing science and threatens to do more harm than good. We contrast Dr Tigard's approach with the current literature on blame to promote an alternative strategy that may help to create lasting change in the face of unfortunate error.

Psicobiología de la agresión y la violencia

El presente trabajo expone la revisión y análisis de distintas investigaciones realizadas por múltiples autores quienes han aportado valiosos descubrimientos para la comprensión de las conductas agresivas y los comportamientos violentos de los seres humanos. La agresión y la violencia son conductas bastante complejas que, en dosis moderadas, pueden tener unafunción adaptativa en entornos ambientales exigentes que supongan retos para la supervivencia del individuo. De este modo, la agresión y la violencia podrían considerarse como parte de una misma dimensión continua (Vassos, 2014). Diversos factores psicobiológicos convergen e interactúan en el marco de las causas y consecuencias de la agresión y la violencia, como las bases genéticas (genes y herencia), la neuroquímica del cerebro (neurotransmisores y hormonas), las estructuras subcorticales (hipotálamo, amígdala, corteza cingulada anterior, fascículo uncinado), el desempeño de la corteza prefrontal y las funciones ejecutivas (corteza orbitofrontal, corteza ventromedial, corteza dorsolateral). No podemos olvidar la interacción de los factores anteriormente mencionados con la interacción e influencia de los factores ambientales, psicosociales y culturales en la manifestación de actos violentos por parte de los seres humanos

Neurobiological correlates in forensic assessment: a systematic review

BACKGROUND

With the increased knowledge of biological risk factors, interest in including this information in forensic assessments is growing. Currently, forensic assessments are predominantly focused on psychosocial factors. A better understanding of the neurobiology of violent criminal behaviour and biological risk factors could improve forensic assessments.

OBJECTIVE

To provide an overview of the current evidence about biological risk factors that predispose people to antisocial and violent behaviour, and determine its usefulness in forensic assessment.

METHODS

A systematic literature search was conducted using articles from PsycINFO, Embase and Pubmed published between 2000 and 2013.

RESULTS

This review shows that much research on the relationship between genetic predisposition and neurobiological alterations with aggression is performed on psychiatric patients or normal populations. However, the number of studies comparing offenders is limited. There is still a great need to understand how genetic and neurobiological alterations and/or deficits are related to violent behaviour, specifically criminality. Most studies focus on only one of the genetic or neurobiological fields related to antisocial and/or violent behaviour. To reliably correlate the findings of these fields, a standardization of methodology is urgently needed.

CONCLUSION

Findings from the current review suggest that violent aggression, like all forms of human behaviour, both develops under specific genetic and environmental conditions, and requires interplay between these conditions. Violence should be considered as the end product of a chain of life events, during which risks accumulate and potentially reinforce each other, displaying or triggering a specific situation. This systematic review did not find evidence of predispositions or neurobiological alterations that solely explain antisocial or violent behaviour. With better designed studies, more correlation between diverse fields, and more standardisation, it might be possible to elucidate underlying mechanisms. Thus, we advocate maintaining the current case-by-case differentiated approach to evidence-based forensic assessment.

Brains in context in the neurolaw debate: the examples of free will and "dangerous" brains

Will neuroscience revolutionize forensic practice and our legal institutions? In the debate about the legal implications of brain research, free will and the neural bases of antisocial or criminal behavior are of central importance. By analyzing frequently quoted examples for the unconscious determinants of behavior and antisocial personality changes caused by brain lesions in a wider psychological and social context, the paper argues for a cautious middle position: Evidence for an impending normative "neuro-revolution" is scarce and neuroscience may instead gradually improve legal practice in the long run, particularly where normative questions directly pertain to brain-related questions. In the conclusion the paper raises concerns that applying neuroscience methods about an individual's responsibility or dangerousness is premature at the present time and carries serious individual and societal risks. Putting findings from brain research in wider contexts renders them empirically investigable in a way that does not neglect psychological and social aspects of human mind and behavior.