Is Psychopathy a Mental Disorder or an Adaptation? Evidence From a Meta-Analysis of the Association Between Psychopathy and Handedness

2021 ◽  
Vol 19 (4) ◽  
pp. 147470492110404
Author(s):  
Lesleigh E. Pullman ◽  
Nabhan Refaie ◽  
Martin L. Lalumière ◽  
DB Krupp
Keyword(s):  
Mental Health ◽  
Life History ◽  
Natural Selection ◽  
Mental Disorder ◽  
Meta Analysis ◽  
Life History Strategy ◽  
Adaptive Strategy ◽  
Strategy Model ◽  
Mental Health Patients ◽  
Competing Models

Psychopathy has historically been conceptualized as a mental disorder, but there is growing evidence that it may instead be an alternative, adaptive life history strategy designed by natural selection. Although the etiology of mental disorders is not fully understood, one likely contributor is perturbations affecting neurodevelopment. Nonright-handedness is a sign of such perturbations, and therefore can be used to test these competing models. If psychopathy is a mental disorder, psychopaths should show elevated rates of nonright-handedness. However, an adaptive strategy perspective expects psychopaths to be neurologically healthy and therefore predicts typical rates of nonright-handedness. We meta-analyzed 16 studies that investigated the association between psychopathy and handedness in various populations. There was no difference in the rates of nonright-handedness between community participants high and low in psychopathy. Furthermore, there was no difference between psychopathic and nonpsychopathic offenders in rates of nonright-handedness, though there was a tendency for offenders scoring higher on the Interpersonal/Affective dimension of psychopathy to have lower rates of nonright-handedness, and for offenders scoring higher on the Behavioral dimension of psychopathy to have higher rates of nonright-handedness. Lastly, there was no difference in rates of nonright-handedness between psychopathic and nonpsychopathic mental health patients. Thus, our results fail to support the mental disorder model and partly support the adaptive strategy model. We discuss limitations of the meta-analysis and implications for theories of the origins of psychopathy.

scholarly journals Prevalence of childhood mental disorders in high-income countries: a systematic review and meta-analysis to inform policymaking

2021 ◽  
pp. ebmental-2021-300277
Author(s):  
Jenny Lou Barican ◽  
Donna Yung ◽  
Christine Schwartz ◽  
Yufei Zheng ◽  
Katholiki Georgiades ◽  
...  
Keyword(s):  
Mental Health ◽  
Mental Disorders ◽  
Mental Disorder ◽  
Service Use ◽  
Mental Health Problems ◽  
Meta Analysis ◽  
Epidemiological Studies ◽  
High Income ◽  
Significant Heterogeneity ◽  
Oppositional Defiant

QuestionMental disorders typically start in childhood and persist, causing high individual and collective burdens. To inform policymaking to address children’s mental health in high-income countries we aimed to identify updated data on disorder prevalence.MethodsWe identified epidemiological studies reporting mental disorder prevalence in representative samples of children aged 18 years or younger—including a range of disorders and ages and assessing impairment (searching January 1990 through February 2021). We extracted associated service-use data where studies assessed this. We conducted meta-analyses using a random effects logistic model (using R metafor package).FindingsFourteen studies in 11 countries met inclusion criteria, published from 2003 to 2020 with a pooled sample of 61 545 children aged 4–18 years, including eight reporting service use. (All data were collected pre-COVID-19.) Overall prevalence of any childhood mental disorder was 12.7% (95% CI 10.1% to 15.9%; I2=99.1%). Significant heterogeneity pertained to diagnostic measurement and study location. Anxiety (5.2%), attention-deficit/hyperactivity (3.7%), oppositional defiant (3.3%), substance use (2.3%), conduct (1.3%) and depressive (1.3%) disorders were the most common. Among children with mental disorders, only 44.2% (95% CI 37.6% to 50.9%) received any services for these conditions.ConclusionsAn estimated one in eight children have mental disorders at any given time, causing symptoms and impairment, therefore requiring treatment. Yet even in high-income countries, most children with mental disorders are not receiving services for these conditions. We discuss the implications, particularly the need to substantially increase public investments in effective interventions. We also discuss the policy urgency, given the emerging increases in childhood mental health problems since the onset of the COVID-19 pandemic (PROSPERO CRD42020157262).

scholarly journals MENTAL HEALTH IN THE PANDEMIC TIMES

2020 ◽  
Vol 4 (3) ◽  
pp. 67-78
Author(s):  
MONIKA FRĄCKOWIAK-SOCHAŃSKA
Keyword(s):  
Mental Health ◽  
Mental Disorder ◽  
Health Care Systems ◽  
Meta Analysis ◽  
Public Mental Health ◽  
Health Issues ◽  
The Public ◽  
Care Systems ◽  
Public Mental Health Care ◽  
Isolation Requirements

The primary aim of this paper is an attempt at the analysis of the prospective direct and indirect, short- and long-term consequences of COVID-19 pandemic for the individuals’ mental health. The secondary aim is to deconstruct the binarity of categories of “mental health” and “mental disorder” in the context of the global critical situation. The pandemic and its consequences such as isolation requirements as well as uncertainty in diverse aspects of life burden the individuals with the stress that results in the increase of anxiety and depressiveness, which challenges the public mental health care systems. Since the anxiety and depressive states are the reactions to a hazardous outside situation, the categories of “mental health” and “mental disorder” needs reconsideration. The theoretical framework of present analyses is determined by the theory of social (cultural) trauma. The method used for the present study is a meta-analysis of theoretical literature, the results of empirical research on COVID-19 pandemic published so far (mostly in medical journals), studies on psychosocial aspects of the previous pandemics (SARS and Ebola), and press publications selected on the basis of their content on mental health issues in the context of the coronavirus pandemic.

scholarly journals Can Functional Traits Explain Plant Coexistence? A Case Study with Tropical Lianas and Trees

Diversity ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 397
Author(s):  
Felipe N. A. Mello ◽  
Sergio Estrada-Villegas ◽  
David M. DeFilippis ◽  
Stefan A. Schnitzer
Keyword(s):  
Life History ◽  
Functional Traits ◽  
Woody Plant ◽  
Meta Analysis ◽  
Life History Strategy ◽  
Life History Strategies ◽  
Morphological And Physiological Traits ◽  
The Mean ◽  
Plant Coexistence

Organisms are adapted to their environment through a suite of anatomical, morphological, and physiological traits. These functional traits are commonly thought to determine an organism’s tolerance to environmental conditions. However, the differences in functional traits among co-occurring species, and whether trait differences mediate competition and coexistence is still poorly understood. Here we review studies comparing functional traits in two co-occurring tropical woody plant guilds, lianas and trees, to understand whether competing plant guilds differ in functional traits and how these differences may help to explain tropical woody plant coexistence. We examined 36 separate studies that compared a total of 140 different functional traits of co-occurring lianas and trees. We conducted a meta-analysis for ten of these functional traits, those that were present in at least five studies. We found that the mean trait value between lianas and trees differed significantly in four of the ten functional traits. Lianas differed from trees mainly in functional traits related to a faster resource acquisition life history strategy. However, the lack of difference in the remaining six functional traits indicates that lianas are not restricted to the fast end of the plant life–history continuum. Differences in functional traits between lianas and trees suggest these plant guilds may coexist in tropical forests by specializing in different life–history strategies, but there is still a significant overlap in the life–history strategies between these two competing guilds.

scholarly journals Effects of parental mental illness on children's physical health: systematic review and meta-analysis

2019 ◽  
Vol 217 (1) ◽  
pp. 354-363 ◽  
Author(s):  
Matthias Pierce ◽  
Holly F. Hope ◽  
Adekeye Kolade ◽  
Judith Gellatly ◽  
Cemre Su Osam ◽  
...  
Keyword(s):  
Mental Health ◽  
Mental Disorder ◽  
Physical Health ◽  
Meta Analysis ◽  
Perinatal Outcomes ◽  
Evidence Base ◽  
Parental Mental Illness ◽  
Physical And Mental Health ◽  
Post Traumatic Stress ◽  
Case Control Studies

BackgroundChildren of parents with mental disorder face multiple challenges.AimsTo summarise evidence about parental mental disorder and child physical health.MethodWe searched seven databases for cohort or case–control studies quantifying associations between parental mental disorders (substance use, psychotic, mood, anxiety, obsessive–compulsive, post-traumatic stress and eating) and offspring physical health. Studies were excluded if: they reported perinatal outcomes only (<28 days) or outcomes after age 18; they measured outcome prior to exposure; or the sample was drawn from diseased children. A meta-analysis was conducted. The protocol was registered on the PROSPERO database (CRD42017072620).ResultsSearches revealed 15 945 non-duplicated studies. Forty-one studies met our inclusion criteria: ten investigated accidents/injuries; eight asthma; three other atopic diseases; ten overweight/obesity; ten studied other illnesses (eight from low-and middle-income countries (LMICs)). Half of the studies investigated maternal perinatal mental health, 17% investigated paternal mental disorder and 87% examined maternal depression. Meta-analysis revealed significantly higher rates of injuries (OR = 1.15, 95% CI 1.04–1.26), asthma (OR = 1.26, 95% CI 1.12–1.41) and outcomes recorded in LMICs (malnutrition: OR = 2.55, 95% CI 1.74–3.73; diarrhoea: OR = 2.16, 95% CI 1.65–2.84). Evidence was inconclusive for obesity and other atopic disorders.ConclusionsChildren of parents with mental disorder have health disadvantages; however, the evidence base is limited to risks for offspring following postnatal depression in mothers and there is little focus on fathers in the literature. Understanding the physical health risks of these vulnerable children is vital to improving lives. Future work should focus on discovering mechanisms linking physical and mental health across generations.Declaration of interestNone.

scholarly journals Does variation in glucocorticoid regulation predict fitness? A phylogenetic meta-analysis

2019 ◽  
Author(s):  
Laura A. Schoenle ◽  
Cedric Zimmer ◽  
Eliot T. Miller ◽  
Maren N. Vitousek
Keyword(s):  
Life History ◽  
Reproductive Success ◽  
Individual Variation ◽  
Meta Analysis ◽  
Life History Strategy ◽  
Population Variation ◽  
Causal Effects ◽  
Coping Capacity ◽  
Negatively Associated ◽  
Context Dependent

ABSTRACTGlucocorticoid hormones (GCs) are central mediators of metabolism and the response to challenges. Because circulating levels of GCs increase in response to challenges, within-population variation in GCs could reflect individual variation in condition or experience. At the same time, individual variation in the degree to which GCs increase in response to challenges (which is relatively consistent within individuals over time) could have causal effects on stress coping capacity, and the ability to survive and reproduce. Although a number of studies in vertebrates have tested whether within-population variation in GCs predicts components of fitness, it is not clear whether there are consistent patterns across taxa. Here we present the first phylogenetic meta-analysis testing whether within-population variation in GCs is associated with components of fitness across vertebrates. At the same time, we introduce and test predictions about an overlooked but potentially important mediator of GC-fitness relationships: life history context. We suggest that strong context-dependence in the fitness benefit of maintaining elevated GCs could obscure consistent patterns between GCs and fitness across taxa. Meta-analyses revealed that across vertebrates, baseline and stress-induced GCs were consistently negatively correlated with reproductive success. This relationship did not differ depending on life history context. In contrast, the relationships between GCs and survival were highly context dependent, differing according to life history strategy. Both baseline and stress-induced GCs were more strongly negatively associated with survival in longer-lived populations and species. Stress-induced GCs were also more negatively associated with survival in organisms that engage in relatively more valuable reproductive attempts. Fecal GCs did not predict survival or reproductive success. We also used a meta-analytic approach to test whether experimental increases in GCs had consistent causal effects on fitness. Experimental increases in GCs reduced both survival and reproductive success, although the latter relationship was not significant when accounting for phylogeny. Overall, these results support the prediction that GC-fitness relationships can be strongly context dependent, and suggest that incorporating life history may be particularly important for understanding GC-survival relationships. Future studies that explore the role of other aspects of context (e.g., the nature and frequency of stressors, environmental variation) within and across species could provide important insights how and when variation in GC regulation predicts fitness.

The effect of early childhood intervention on risk-taking, mental health, and cognitive ability: The mediating role of life history strategy.

2021 ◽  
Vol 15 (1) ◽  
pp. 27-41
Author(s):  
Curtis S. Dunkel ◽  
Jonathan J. Hammersley ◽  
Micheal L. Waters ◽  
Dimitri van der Linden ◽  
Laureon A. Merrie ◽  
...  
Keyword(s):  
Mental Health ◽  
Early Childhood ◽  
Life History ◽  
Cognitive Ability ◽  
Risk Taking ◽  
Life History Strategy ◽  
Early Childhood Intervention ◽  
Mediating Role ◽  
Childhood Intervention

scholarly journals Revisiting the concept of Beverton­­–Holt life-history invariants with the aim of informing data-poor fisheries assessment

2014 ◽  
Vol 72 (1) ◽  
pp. 194-203 ◽  
Author(s):  
Jeremy Prince ◽  
Adrian Hordyk ◽  
Sarah R. Valencia ◽  
Neil Loneragan ◽  
Keith Sainsbury
Keyword(s):  
Life History ◽  
Meta Analysis ◽  
Reproductive Potential ◽  
Life History Strategy ◽  
Marine Species ◽  
Small Scale ◽  
Implicit Assumption ◽  
Fish Stocks ◽  
Assessment Techniques ◽  
The Relationship

Abstract The complexity and cost of assessment techniques prohibits their application to 90% of fisheries. Simple generic approaches are needed for the world's small-scale and data-poor fisheries. This meta-analysis of the relationship between spawning potential and the normalized size and age of 123 marine species suggests that the so-called Beverton–Holt life-history invariants (BH-LHI; Lm/L∞, M/k, M × Agem) actually vary together in relation to life-history strategy, determining the relationship between size, age, and reproductive potential for each species. Although little realized, the common assumption of unique values for the BH-LHI also implies that all species share the same relationship between size, age, and reproductive potential. This implicit assumption is not supported by this meta-analysis, which suggests that there is considerable but predictable natural variation in the BH-LHI ratios and the relationships between size, age, and reproductive potential that they determine. We believe that this reconceptualization of the BH-LHI has potential to provide a theoretical framework for “borrowing” knowledge from well-studied species to apply to related, unstudied species and populations, and when applied together with the assessment technique described by Hordyk et al. (2015b), could make simple forms of size-based assessment possible for many currently unassessable fish stocks.

scholarly journals Evolution in plant populations as a driver of ecological changes in arthropod communities

2009 ◽  
Vol 364 (1523) ◽  
pp. 1593-1605 ◽  
Author(s):  
Marc T.J. Johnson ◽  
Mark Vellend ◽  
John R. Stinchcombe
Keyword(s):  
Genetic Variation ◽  
Life History ◽  
Natural Selection ◽  
Life History Strategy ◽  
Directional Selection ◽  
Oenothera Biennis ◽  
Plant Populations ◽  
Arthropod Species ◽  
Ecological Changes ◽  
Evolution By Natural Selection

Heritable variation in traits can have wide-ranging impacts on species interactions, but the effects that ongoing evolution has on the temporal ecological dynamics of communities are not well understood. Here, we identify three conditions that, if experimentally satisfied, support the hypothesis that evolution by natural selection can drive ecological changes in communities. These conditions are: (i) a focal population exhibits genetic variation in a trait(s), (ii) there is measurable directional selection on the trait(s), and (iii) the trait(s) under selection affects variation in a community variable(s). When these conditions are met, we expect evolution by natural selection to cause ecological changes in the community. We tested these conditions in a field experiment examining the interactions between a native plant ( Oenothera biennis ) and its associated arthropod community (more than 90 spp.). Oenothera biennis exhibited genetic variation in several plant traits and there was directional selection on plant biomass, life-history strategy (annual versus biennial reproduction) and herbivore resistance. Genetically based variation in biomass and life-history strategy consistently affected the abundance of common arthropod species, total arthropod abundance and arthropod species richness. Using two modelling approaches, we show that evolution by natural selection in large O. biennis populations is predicted to cause changes in the abundance of individual arthropod species, increases in the total abundance of arthropods and a decline in the number of arthropod species. In small O. biennis populations, genetic drift is predicted to swamp out the effects of selection, making the evolution of plant populations unpredictable. In short, evolution by natural selection can play an important role in affecting the dynamics of communities, but these effects depend on several ecological factors. The framework presented here is general and can be applied to other systems to examine the community-level effects of ongoing evolution.

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