Taxonomies of psychological individual differences: biological perspectives on millennia-long challenges

Trait continuity: Can parent-rated infant temperament predict HEXACO personality in early adulthood?

Examining the Raine cohort study, we tested the trait continuity hypothesis by examining the extent that young adults' (25-29 years old) self-reported HEXACO personality can be statistically predicted from multi-dimensional parental temperament ratings collected in infancy (1-2 years old). The study incorporated a lagged design (two waves), a large sample size (n = 563), and examined both temperament and personality as both dimensions and profiles. Overall, we found very limited evidence of trait continuity, with generally very weak and few statistically significant observed associations of infant temperament with early adulthood personality. Relations were weak whether profile or dimension-based operationalizations of both phenomena were adopted. Additionally, controlling for sex affected the relations of temperament and personality only to a small extent for most of the traits, and moderation effects of sex were generally zero-to-trivial in size. Altogether, parent-rated temperament in infancy seems to provide little information about HEXACO personality in early adulthood.

Analytic Background in the Neuroscience of the Potential Project "Hippocrates"

This paper reviews the principles identified in analytic neuroscience that could be used in the setup of an international project, "Hippocrates" (H-project), named after the author of the endocrine theory of temperaments. The H-project can aim to summarize the findings in functional neurochemistry of consistent behavioural patterns (CBPs) in health (such as temperament traits) and psychopathology (symptoms of psychiatric disorders); to have systematically structured neurochemical investigations; to have an analysis of CBPs that include all ranges of behavioural histories and to have these modules complemented by regional contrasts related to climate, diets and other bio-environmental factors. The review highlights the benefits of constructivism and illustrates the contrast between constructivism and current approaches in terms of analytic and methodological aspects. (1) "Where" the neurochemical biomarkers should be measured: the review expands the range of needed measurements to out-of-brain systems, including environmental factors, and explores the concept of Specialized Extended Phenotype. (2) "What" should be measured but is missing: the review points to the need for measurement of the "Throw & Catch" neurochemical relays; behavioural and neuronal events contributing to the consistency of the CBPs but not documented in measurements. (3) Structuring the H-project's setup: the paper briefly describes a proposed earlier neurochemical framework, Functional Ensemble of Temperament that that accommodates the neurochemical continuum between temperament and symptoms of psychiatric disorders. This framework is in line with documented "Throw & Catch" neurochemical relays and can also be used to organize data about the personal and professional history of an individual.

Age of Acquisition of Personality Terms: Implications for Personality Theory

Analysis of the age of acquisition (AoA) of personality terms represents a genetic method for the study of the individual personality lexicon and offers a potential alternative to correlational analysis for identifying the fundamental personality descriptors among the thousands of terms that appear in language. In the present study, the relationship between AoA, word frequency, word desirability, and factor loading in the Big Five and Hexaco models of 274 and 408 personality adjectives was analyzed. It was found that young children (2nd graders or younger) acquire personality terms that represent traits at the core of the broad personality factors in the Big Five and Hexaco models slightly earlier than words that represent more peripheral traits. In older children beyond second grade, the correlation between factor loading and AoA is weak. Words that describe the broad openness and stability/emotionality aspects of personality are learned later than words for the other broad factors. Word frequency (in book texts) and desirability have a weak negative correlation with AoA. It is hypothesized that the AoA of a personality term reflects the importance of the corresponding trait for children and may be used as one criterion for ranking facet level traits independent of the broad factors.

Understanding Kindness in the Russian Context

Background

Kindness and acts of kindness have the potential to cause tremendously positive effects on subjective well-being, reflected in improvements in mental and physical health, and interpersonal relationships. Fostering knowledge about kindness may help in self-development and psychotherapeutic interventions aimed to improve an individual's emotional well-being. However, existing research data and understanding of this phenomenon in Russia, as well as descriptions of acts of kindness, are presently relatively limited.

Objective

To study the Russian understanding of kindness, its meaning in the Russian context; to categorize a variety of identified acts of kindness; and to define kindness based on the data derived from a Russian sample.

Design

There were 291 Russian participants, recruited using an online recruiting platform, who filled out an online questionnaire that identified definitions of kindness with corresponding examples. Also captured in the sample were the participant's age, gender, and religiosity. The data underwent qualitative analysis through open, axial, and focused coding.

Results

As a result of qualitative analysis, four theme categories emerged to define kindness: a) personal states and qualities (one's own states and self-perception, moral values and qualities, self-regulation and emotional stability); b) openness to others (attention to others, love and positive attitude); c) emotional and cognitive understanding of others and tolerance, actions and behavior (altruistic sacrifice, help, politeness and respect, forgiveness, generosity, pleasing actions). Concrete examples of kind acts and behavior were categorized. A definition of kindness was formulated based on the data.

Conclusion

The research results can be used in training, counselling, and therapeutic sessions to increase subjective well-being. Directions for further research have been defined.

Emotionality vs. Other Biobehavioural Traits: A Look at Neurochemical Biomarkers for Their Differentiation

This review highlights the differential contributions of multiple neurochemical systems to temperament traits related and those that are unrelated to emotionality, even though these systems have a significant overlap. The difference in neurochemical biomarkers of these traits is analysed from the perspective of the neurochemical model, Functional Ensemble of Temperament (FET) that uses multi-marker and constructivism principles. Special attention is given to a differential contribution of hypothalamic-pituitary hormones and opioid neuropeptides implicated in both emotional and non-emotional regulation. The review highlights the role of the mu-opioid receptor system in dispositional emotional valence and the role of the kappa-opioid system in dispositional perceptual and behavioural alertness. These opioid receptor (OR) systems, microbiota and cytokines are produced in three neuroanatomically distinct complexes in the brain and the body, which all together integrate dispositional emotionality. In contrast, hormones could be seen as neurochemical biomarkers of non-emotional aspects of behavioural regulation related to the construction of behaviour in fast-changing and current situations. As examples of the role of hormones, the review summarised their contribution to temperament traits of Sensation Seeking (SS) and Empathy (EMP), which FET considers as non-emotionality traits related to behavioural orientation. SS is presented here as based on (higher) testosterone (fluctuating), adrenaline and (low) cortisol systems, and EMP, as based on (higher) oxytocin, reciprocally coupled with vasopressin and (lower) testosterone. Due to the involvement of gonadal hormones, there are sex and age differences in these traits that could be explained by evolutionary theory. There are, therefore, specific neurochemical biomarkers differentiating (OR-based) dispositional emotionality and (hormones-based) body's regulation in fast-changing events. Here we propose to consider dispositional emotionality associated with OR systems as emotionality in a true sense, whereas to consider hormonal ensembles regulating SS and EMP as systems of behavioural orientation and not emotionality.

A neurocognitive model of ideological thinking

Ideological behavior has traditionally been viewed as a product of social forces. Nonetheless, an emerging science suggests that ideological worldviews can also be understood in terms of neural and cognitive principles. The article proposes a neurocognitive model of ideological thinking, arguing that ideological worldviews may be manifestations of individuals' perceptual and cognitive systems. This model makes two claims. First, there are neurocognitive antecedents to ideological thinking: the brain's low-level neurocognitive dispositions influence its receptivity to ideological doctrines. Second, there are neurocognitive consequences to ideological engagement: strong exposure and adherence to ideological doctrines can shape perceptual and cognitive systems. This article details the neurocognitive model of ideological thinking and synthesizes the empirical evidence in support of its claims. The model postulates that there are bidirectional processes between the brain and the ideological environment, and so it can address the roles of situational and motivational factors in ideologically motivated action. This endeavor highlights that an interdisciplinary neurocognitive approach to ideologies can facilitate biologically informed accounts of the ideological brain and thus reveal who is most susceptible to extreme and authoritarian ideologies. By investigating the relationships between low-level perceptual processes and high-level ideological attitudes, we can develop a better grasp of our collective history as well as the mechanisms that may structure our political futures.

Temperament Profiles of Children and Adolescents with Psychotic and Mood Disorders

BACKGROUND

Psychiatric disorders are often linked to dysfunctions within neurotransmitter systems, and the same systems play a role in healthy temperaments. Development of a common bio-behavioural taxonomy based on functionality of neurotransmitter systems suggests examining temperament profiles in patients with various psychiatric disorders.

OBJECTIVE

(1) To investigate temperament profiles in two age groups of children with delusional disorders; (2) to investigate temperament profiles in adolescents with mood disorders; (3) to investigate temperament profiles in in vitro fertilisation (IVF) children.

METHODS

Sample: in total 171 participants (M/F = 91/80), healthy children and teenagers (volunteers); two age groups of children with psychotic disorders; teens with mood disorders (clients of the Federal Mental Health Center) and healthy IVF. Parents of participants completed a test based on the neurochemical model Functional Ensemble of Temperament (FET).

RESULTS AND CONCLUSIONS

(1) Both age groups of children with psychotic disorders had significantly lower scores on the scales of physical endurance, tempo, plasticity, and self-satisfaction, in comparison to healthy controls; the psychotic group aged 5-11 had also lower scores on the impulsivity scale, whereas the psychotic group 12-17 had lower scores on the social endurance and social tempo scales and higher neuroticism. (2) Teens with mood disorders had lower scores on the self-confidence-satisfaction scale and higher scores on the impulsivity scale, in comparison to controls. (3) No difference between IVF and naturally conceived children were found. The results show the benefits of using the FET framework for structuring the correspondence between psychiatric disorders and temperament as it differentiates between social versus physical aspects of behaviour and orientational versus executive aspects.

Functional Constructivism Approach to Multilevel Nature of Bio-Behavioral Diversity

Attempts to revise the existing classifications of psychiatric disorders (DSM and ICD) continue and highlight a crucial need for the identification of biomarkers underlying symptoms of psychopathology. The present review highlights the benefits of using a Functional Constructivism approach in the analysis of the functionality of the main neurotransmitters. This approach explores the idea that behavior is neither reactive nor pro-active, but constructive and generative, being a transient selection of multiple degrees of freedom in perception and actions. This review briefly describes main consensus points in neuroscience related to the functionality of eight neurochemical ensembles, summarized as a part of the neurochemical model Functional Ensemble of Temperament (FET). None of the FET components is represented by a single neurotransmitter; all neurochemical teams have specific functionality in selection of behavioral degrees of freedom and stages of action construction. The review demonstrates the possibility of unifying taxonomies of temperament and classifications of psychiatric disorders and presenting these taxonomies formally and systematically. The paper also highlights the multi-level nature of regulation of consistent bio-behavioral individual differences, in line with the concepts of diagonal evolution (proposed earlier) and Specialized Extended Phenotype.

Creative Polymathy and the COVID-19 Crisis

It is increasingly argued that polymathy-vocational and avocational pursuits in multiple domains-is deeply associated with creativity and innovation, and that its development enables the creation of important bridges between otherwise fragmented, dispersed sets of knowledge. Nevertheless, the dominant culture in both industry and academia is still that of narrow specialization. In this paper, we argue that in the context of COVID-19 crisis, with its wicked and transdisciplinary nature, the disciplinary approach of specialization is ill-suited to solve our increasingly complex problems, and that polymathic thinking can be a crucial asset in this regard. Drawing on different literature strands, we first examine the interplay between polymathy and other well-developed constructs in personality and temperament research. We then advance theoretical predictions regarding the relationship between trait polymathy and resilience in the COVID-19 crisis. After that, we discuss learnable strategies that can be used in complex, uncertain and adverse situations, which are associated with development of a more polymathic (broader, deeper and more integrated) set of knowledge. Later, we discuss how it may be possible to better capitalize on the key features of polymathic thinking at the societal level. Finally, we conclude with a reflection on the adequacy of our current institutions for dealing with complex problems, and we underscore the crucial role of polymathic thinking in an increasingly complex and interrelated world.

Quantifying the Predictive Role of Temperament Dimensions and Attachment Styles on the Five Factor Model of Personality

Background: The present study investigated the role of temperament and attachment security in predicting individual differences in the five factor personality traits among adults. As previous studies suggested the potential moderating role of attachment in the association between temperament and personality traits, the present study sought to examine an interactionist model combining attachment and temperament in explaining individual differences in personality traits. Methods: A sample of 1871 participants (1151 women and 719 men) completed self-report measures of adult attachment style (the Relationships Questionnaire—RQ), temperament dimension (the Fisher Temperament Inventory—FTI), and personality domain (the Five Factor Model—FFM). Results: Partial correlational analyses revealed associations between attachment security and each of the five domains of the FFM, and few associations between some temperament dimensions and several domains of the FFM. Moderated regression analyses showed that attachment security moderated the associations between temperament dimensions and the Agreeableness domain of the FFM. Among secure individuals, those with higher scores on the Curious/Energetic, Cautious/Social Norm Compliant and Prosocial/Empathetic scales exhibited higher Agreeableness scores, whereas among insecure individuals, those with higher scores on the Analytic/Tough-minded scale exhibited lower scores on the Agreeableness scale. Conclusion: Overall, the current study provides evidence in support of the substantive role of social-environmental factors (Adult Attachment) as a moderating element bridging temperament-related personality elements and a number of their FFM manifestations.

Taxonomic models of individual differences: a guide to transdisciplinary approaches

Models and constructs of individual differences are numerous and diverse. But detecting commonalities, differences and interrelations is hindered by the common abstract terms (e.g. 'personality', 'temperament', 'traits') that do not reveal the particular phenomena denoted. This article applies a transdisciplinary paradigm for research on individuals that builds on complexity theory and epistemological complementarity. Its philosophical, metatheoretical and methodological frameworks provide concepts to differentiate various kinds of phenomena (e.g. physiology, behaviour, psyche, language). They are used to scrutinize the field's basic concepts and to elaborate methodological foundations for taxonomizing individual variations in humans and other species. This guide to developing comprehensive and representative models explores the decisions taxonomists must make about which individual variations to include, which to retain and how to model them. Selection and reduction approaches from various disciplines are classified by their underlying rationales, pinpointing possibilities and limitations. Analyses highlight that individuals' complexity cannot be captured by one universal model. Instead, multiple models phenotypically taxonomizing different kinds of variability in different kinds of phenomena are needed to explore their causal and functional interrelations and ontogenetic development that are then modelled in integrative and explanatory taxonomies. This research agenda requires the expertise of many disciplines and is inherently transdisciplinary.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'.

Diversity in action: exchange of perspectives and reflections on taxonomies of individual differences

Throughout the last 2500 years, the classification of individual differences in healthy people and their extreme expressions in mental disorders has remained one of the most difficult challenges in science that affects our ability to explore individuals' functioning, underlying psychobiological processes and pathways of development. To facilitate analyses of the principles required for studying individual differences, this theme issue brought together prominent scholars from diverse backgrounds of which many bring unique combinations of cross-disciplinary experiences and perspectives that help establish connections and promote exchange across disciplines. This final paper presents brief commentaries of some of our authors and further scholars exchanging perspectives and reflecting on the contributions of this theme issue.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'.

There is more to mental illness than negative affect: comprehensive temperament profiles in depression and generalized anxiety

BACKGROUND

Temperament and mental illness are thought to represent varying degrees along the same continuum of neurotransmitter imbalances. A taxonomy of temperament could provide the basis for a new taxonomy of mental illness. Most popular models of temperament, being based heavily on emotionality traits, show very poor ability to discriminate between mental disorders. The main goal of this study was to examine whether a temperament model based on modern neurophysiology and possessing an extensive set of non-emotionality traits provides better discrimination between Major Depression (MD), Generalized Anxiety (GAD) and Comorbid MD and GAD, in comparison to emotionality-based temperament models.

METHODS

Using the Structure of Temperament Questionnaire, the temperament profiles of 687 individuals (396 clients of private psychiatric and psychological practice, and 291 control subjects) were compared across four adult age groups (18-24, 25-45, 46-65, 66-84).

RESULTS

MD and GAD appear to be accurately distinguished by the traits of Motor Endurance and Motor Tempo (much lower values in depression), and Neuroticism (much higher value in anxiety). Comorbids can be distinguished based on a significant decrease in the traits of Plasticity, Intellectual Endurance, Sensitivity to Probabilities, and increased Impulsivity. These effects seemed independent of age and gender.

CONCLUSIONS

The results suggest the benefits of including non-emotionality-related traits and the usefulness of a functional approach to both taxonomy of temperament and classification of mental disorders.

Functionality versus dimensionality in psychological taxonomies, and a puzzle of emotional valence

This paper applies evolutionary and functional constructivism approaches to the discussion of psychological taxonomies, as implemented in the neurochemical model Functional Ensemble of Temperament (FET). FET asserts that neurochemical systems developed in evolution to regulate functional-dynamical aspects of construction of actions: orientation, selection (integration), energetic maintenance, and management of automatic behavioural elements. As an example, the paper reviews the neurochemical mechanisms of interlocking between emotional dispositions and performance capacities. Research shows that there are no specific neurophysiological systems of positive or negative affect, and that emotional valence is rather an integrative product of many brain systems during estimations of needs and the capacities required to satisfy these needs. The interlocking between emotional valence and functional aspects of performance appears to be only partial since all monoamine and opioid receptor systems play important roles in non-emotional aspects of behaviour, in addition to emotionality. This suggests that the Positive/Negative Affect framework for DSM/ICD classifications of mental disorders oversimplifies the structure of non-emotionality symptoms of these disorders. Contingent dynamical relationships between neurochemical systems cannot be represented by linear statistical models searching for independent dimensions (such as factor analysis); nevertheless, these relationships should be reflected in psychological and psychiatric taxonomies.This article is part of the theme issue 'Diverse perspectives on diversity: multi-disciplinary approaches to taxonomies of individual differences'.