Variation In Personality Traits Research Articles

An investigation of personality in the Creek Chub, Semotilus atromaculatus

AbstractIntraspecific variation in personality traits is increasingly recognized as an important driver of ecological processes, particularly within the context of species invasions. However, relatively few studies have investigated personality in native fauna with more localized dispersal patterns, and information regarding the existence of personality in stream fishes native to the southeastern US is particularly lacking. In this study, we investigated personality in a native and widespread minnow species, the Creek Chub (Semotilus atromaculatus). Because of its piscivorous diet, use of its nests by nest-associating minnows, and its role as a colonizer of intermittent streams, the Creek Chub is an appropriate species for investigating the broad importance of personality-dependent processes to stream communities. We identified personality traits by estimating the repeatability of sociability, boldness, exploration, and activity in two separate behavioral assays and interpreted correlations between traits as evidence of behavioral syndromes. We did not detect repeatability for measures of sociability, possibly due to predatory interactions within this species. However, boldness, exploration, and activity were significantly repeatable and positively correlated, pointing to the existence of a bold-exploratory-active syndrome in this species. Larger individuals tended to be less active, and, despite a relatively small sample size, we detected significant differences between source populations for measures of boldness. This is the first study to identify the existence of a behavioral syndrome in Creek Chub and points to the importance of considering the role of personality in ecological processes involving native fauna.

Animal personalities influence male mating behavior and reproductive fitness

Abstract The relationship between individual personality and sexual selection has the potential to provide insights into how variation in personality traits is maintained. However, whether and how individuals with different personality traits have different mating behaviors and the fitness consequences has remained largely unexplored. We tested the hypothesis that male individuals have different mating behavior depending on their personality traits, and that there are fitness effects of personality traits. To do so, we conducted trials to quantify personality traits and observed mating behavior under standardized conditions in the red flour beetle (Tribolium castaneum). We also collected the number of offspring produced by their female mates to assess the association between male personality and their reproductive fitness. We found that male beetles showed consistent inter-individual differences in walking distance, emergence time from shelter and death-feigning time, which likely corresponding to two personality traits of activity and boldness. Although larger males had higher mating success and produced more offspring, some personality traits were also strongly related to mating behavior and reproductive fitness. Males with longer walking distances tended to seek female mates more promptly. Other than the morphological trait of body size, the emergence time from shelter (boldness) also showed a positive relationship with the number of matings and offspring reproduced. Furthermore, we found that the interaction between death-feigning time and walking distance in males influenced the number of matings they obtain, with either shy but active or bold but inactive males achieving more matings. We therefore highlight that alongside morphological traits, certain personality traits can also play a role in affecting mating behaviors and even reproductive fitness in males.

Variations in Personality Traits Among Top Judo Referees from 2018 to 2022 Based on Gender Differences

The personality traits of top judo referees are crucial for fair decision-making in elite competitions, shaping the experience for athletes, coaches, and spectators. This study examines potential differences in personality traits among 63 referees from the World Judo Tour between 1 January 2018 and 31 December 2022. Factors analyzed include completing the IJF Academy course Level 1, elite athlete status, number of officiated events, performance ratings, and participation in the Olympic or Paralympic Games. Our research shows that older referees tend to exhibit greater extraversion, whereas less experienced officials show lower levels of this trait. Referees with limited experience generally demonstrate higher agreeableness than their more experienced counterparts. Female referees and those with top performance ratings display greater conscientiousness than male referees. Completing the IJF Academy course is associated with lower neuroticism, while lower performance ratings are linked to higher neuroticism. Openness tends to decrease with increased officiating experience, with less experienced referees showing higher levels of this trait. In conclusion, competitive experience, training completion, and officiating tenure are associated with specific personality traits among judo referees, highlighting the importance of continuous training for effective officiating. The analysis of personality traits revealed no statistically significant differences between male and female referees in the dimensions measured by the BFI (Big Five Inventory). This indicates that the levels of extraversion, agreeableness, conscientiousness, neuroticism, and openness were similar for both genders, with no significant variation in how these traits were expressed.

Going urban: variation in personality traits of an invasive species along an urbanization gradient

Abstract The fast-growing expansion of urban areas pose severe pressures on wildlife. However, some generalist native mammals thrive in urbanized landscapes, while invasive alien species (IAS) are often more abundant in cities than in rural habitats. Variation in phenotypes—such as differences in personality traits—can influence the probability to colonize anthropized areas, especially in the case of IAS where certain traits are related to invasion success. Here, we investigated the expression of activity, exploration, and social tendency in the invasive alien Eastern Gray Squirrel (Sciurus carolinensis) in replicated study sites along a rural–urban gradient in Northern Italy. Personality traits expression was estimated using an open field test (OFT) followed by a mirror image stimulation (MIS) test. We found that squirrels were more active in urban than in suburban and rural sites, and behaved more sociable in urban than in suburban sites. Conversely, exploration did not differ along the gradient. Results also reveal the presence of a behavioral syndrome: activity (OFT), social tendency, and activity–exploration (MIS). We suggest that variation in activity level and social behavior in urban habitats could favor some species to respond positively to urbanization. This study sheds light on the underexplored personality–urbanization relationship in IAS, helping to understand the complex process of invasion.

Born to move? Birth order and emigration

This paper studies the interrelation between birth order and emigration adopting a family fixed-effects approach. We use register data on all persons in full-siblings groups born 1970–2002 in the entire Finnish-born population, and observe their first move abroad since age 18 in the period 1987–2020. The total number of siblings is 1,352,908, the total number of sibling groups 549,842, and the total number of first moves abroad 31,192. By comparing siblings in the same family, we effectively adjust for all time-invariant confounding from unobserved or unmeasured time-invariant variables. Emigration is found to be positively associated with birth order. The hazard of emigration for second-born siblings is 1.05 that of first borns, that of third borns 1.07, and that of fourth borns 1.11. The pattern is particularly marked for emigration to countries where there is free mobility, and the association is similar for both genders. Potential explanations to the birth order pattern may be variation in personality traits, risk-taking behaviours and aspirations between siblings, or differential allocation of resources and opportunities within families. The results highlight the importance of considering birth order within the context of family dynamics and individual mobility patterns, and they need to be extended to broader settings.

Measuring the variability of personality traits with interval responses: Psychometric properties of the dual-range slider response format

Measuring the variability in persons’ behaviors and experiences using ecological momentary assessment is time-consuming and costly. We investigate whether interval responses provided through a dual-range slider (DRS) response format can be used as a simple and efficient alternative: Respondents indicate variability in their behavior in a retrospective rating by choosing a lower and an upper bound on a continuous, bounded scale. We investigate the psychometric properties of this response format as a prerequisite for further validation. First, we assess the test–retest reliability of factor-score estimates for the width of DRS intervals. Second, we test whether factor-score estimates of the visual analog scale (VAS) and the location of DRS intervals show convergent validity. Third, we investigate whether factor-score estimates for the DRS are uncorrelated between different personality scales. We present a longitudinal multitrait-multimethod study using two personality scales (Extraversion, Conscientiousness) and two response formats (VAS, DRS) at two measurement occasions (6–8 weeks apart) for which we estimate factor-score correlations in a joint item response theory model. The test–retest reliability of the width of DRS intervals was high (ρ^≥.73\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hat{\\rho } \\ge .73$$\\end{document}). Also, convergent validity between location scores of VAS and DRS was high (ρ^≥.88\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hat{\\rho } \\ge .88$$\\end{document}). Conversely, discriminant validity of the width of DRS intervals between Extraversion and Conscientiousness was poor (ρ^≥.94\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hat{\\rho } \\ge .94$$\\end{document}). In conclusion, the DRS seems to be a reliable response format that could be used to measure the central tendency of a trait equivalently to the VAS. However, it might not be well suited for measuring intra-individual variability in personality traits.

Are There Variations in Personality Traits Between Men and Women? The Evidence is from Indonesian Residents

Non-cognitive skills, such as personality traits, play a vital role in various facets of human life due to their association with individual decision-making. However, personality traits can vary significantly among individuals globally, particularly between males and females. Hence, the primary objective of this study is to analyze the disparities in personality traits between men and women and to investigate how non-cognitive skills influence well-being. The study utilizes nationally representative data from Indonesia, encompassing 17,560 men and 18,825 women. Employing distinct mean t-tests and linear regression estimations, we observe that men tend to exhibit higher levels of openness, conscientiousness, and agreeableness in their personalities compared to women. Conversely, women demonstrate a propensity for higher level of extraversion and neuroticism. Moreover, our analysis reveals that male well-being is positively correlated with extraversion, while female well-being is linked to openness and extraversion traits. These findings underscore the significance of considering personality attributes in crafting economic development policies. Presently, policymakers in emerging nations like Indonesia heavily prioritize cognitive skills such as technical training and technological innovation. This study suggests that incorporating residents' non-cognitive talents into policy-making could potentially lead to enhanced achievements and progress.

Igniting work innovation: performance pressure, extraversion, feedback seeking and innovative behavior

PurposeThis study investigates how performance pressure affects feedback-seeking and innovative work behaviors. The study also examines the effect of extraversion on the performance pressure–FSB relationship.Design/methodology/approachThe hypotheses in this study were tested by analyzing two-wave data collected from a sample of employees in the information technology sector in India using the PLS-SEM approach.FindingsOur findings revealed that individuals possessing extraverted personality traits exhibited a positive response to performance pressure, thereby enhancing their FSB. Moreover, our results demonstrated that FSB mediates the relationship between performance pressure and IWB.Research limitations/implicationsThe results underscore the importance of individual variations in personality traits, particularly extraversion, in influencing how employees respond to performance pressure. By providing insights into the mediating mechanism of feedback-seeking behavior, our study contributes to a deeper understanding of the interplay between performance pressure, feedback-seeking behavior and innovative work behavior.Practical implicationsManagers should consider extraversion as a factor in the relationship between performance pressure and FSB, adapting strategies and support systems accordingly. Creating a feedback-oriented culture and providing resources for extroverts during high-pressure periods can enhance their coping mechanisms.Originality/valuePrevious research has provided a limited exploration of the mechanisms that establish the connection between job demands and innovative work behaviors. This study contributes by uncovering the previously unexplored relationship between performance pressure, extraversion, feedback-seeking behavior and, subsequently, innovative work behavior.

Personality differences among acculturation profiles of Chinese domestic migrants: A person-centered approach

We explored acculturation profiles among Chinese domestic migrants and examined the variation in personality traits across these profiles. Questionnaires assessing acculturation patterns and personality traits were completed by 816 participants. Acculturation patterns were measured by the East Asian Acculturation Measure and personality traits were measured with the Eysenck Personality Questionnaire???Revised, Short Scale. Four profiles with personality differences were identified using latent profile analysis: less acculturated, highlyacculturated,marginalized,andmoderatelybicultural.Adoptingapersoncentered approach was underscored by these findings, suggesting that the government could design a targeted strategy aimed at facilitating adjustment among higher risk domestic migrants (e.g., those with marginalized or less-acculturated profiles) with particular personality traits, such as high levels of neuroticism and low extraversion.

Beyond traditional interviews: Psychometric analysis of asynchronous video interviews for personality and interview performance evaluation using machine learning

With the advent of new technology, traditional job interviews have been supplemented by asynchronous video interviews (AVIs). However, research on psychometric properties of AVIs is limited. In this study, 710 participants completed a mock AVI responding to eight personality questions (Extraversion, Conscientiousness). We collected self- and observer reports of personality, interview performance ratings, attractiveness, and AVI meta-information (e.g., professional attire, audio quality). Then, we automatically extracted the words, facial expressions, and voice characteristics from the videos and trained machine learning models to predict the personality traits and interview performance. Our algorithm explained substantially more variance in observer reports of Extraversion and Conscientiousness (average R2 = 0.32) and interview performance (R2 = 0.44), than self-reported Extraversion and Conscientiousness (average R2 = 0.12). Consistent with Trait Activation Theory, the explained variance in personality traits increased when participants responded to trait-relevant, compared to trait-irrelevant, questions. The test-retest reliability of our algorithm was somewhat stable over a time period of seven months, but lower than desired reliability standards in personnel selection. We examined potential sources of bias, including age, gender, and attractiveness, and found some instances of algorithmic bias (e.g., gender differences were often amplified in favor of women).

Factor Structure and Reliability of Big Five Inventory: A Study on Indian Tribal Population

The Current study aimed to investigate the structural organization of the Big Five Personality Inventory developed by John & Srivastava. The study comprises of 140 tribal students belonging to various tribal communities and groups making a composition of Adi, Galo, Nyshii, and Apattani to be found mostly in the University’s premises. The primary data has been collected by administering a Big Five Personality Inventory. The reliability and factor structure of the inventory were measured. Among the total of 44 items, the total five major factors were extracted, representing only three main items in each factor with high factor loading, these five factors collectively accounted for 66.88% of total variance in personality traits on the sample of tribal students. The correlation matrix table revealed that extraversion exhibited strong inter correlations with agreeableness, conscientiousness, and neuroticism.

Alike but not the same: Psychological profiles of COVID-19 vaccine skeptics.

One of the challenges of the SARS-CoV-2 pandemic was a widespread skepticism about vaccination. To elucidate the underlying mental and emotional predispositions, we examined a sample of 1428 participants using latent profile analysis (LPA) on selected personality trait variables, mental health status, and measures of irrational beliefs. LPA revealed five distinct profiles: two classes of non-skeptics and three of skeptics. The smaller non-skeptic class reported the highest rates of mental health problems, along with high levels of neuroticism, hostility, interpersonal sensitivity, and external locus of control. The larger non-skeptic class was psychologically well-balanced. Conversely, the skeptic groups shared strong distrust of COVID-19 vaccination but differed in emotional and mental profiles, leading to graded differences in endorsing extreme conspiracy beliefs. This suggests that vaccine skepticism is not solely a result of mental illness or emotional instability; rather extreme skepticism manifests as a nuanced, graded phenomenon contingent on personality traits and conspirational beliefs.

Exploratory behavior is associated with the cognitive speed in male chestnut thrushes

Abstract Intra-individual variation in cognitive abilities has been widely reported in animals. Recent studies have found that individual cognitive performance varies with personality traits in a wide range of animal taxa, with a speed-accuracy trade-off between cognition and personality traits. Few studies investigated whether these relationships change depending on different contexts. Here we investigate whether the personality trait (as measured by exploratory behavior in a novel environment) is associated with cognition (novel skill learning and spatial memory) in wild male chestnut thrushes Turdus rubrocanus. Using an experimental novel skill-learning task set-up, we found that fast-exploring individuals explored the experimental device (a cardboard with 8 opaque cups) sooner than slow-exploring individuals. Exploratory behavior was not associated with individual spatial memory performances or an individual’s capacity to learn the novel skill. Learning speed was positively associated with the difficulty of learning phases, and fast-exploring individuals used less trials to meet the learning criterion. In addition, fast-exploring individuals took less time to complete the 24-h spatial memory test, but the accuracy of the test was not significantly different between individuals who were more or less exploratory. We suggest that variation in personality traits associates with individual learning speed in cognitive tasks and that this relationship is context-dependent.

High-frequency assessment of mood, personality, and cognition in healthy younger, healthy older and adults with cognitive impairment

ABSTRACT Increased variability in cognitive scores, mood or personality traits can be indicative of underlying neurological disorders. Whether variability in cognition is due to changes in mood or personality is unknown. A total of 66 younger adults, 51 healthy older adults and 38 participants with cognitive impairment completed 21 daily sessions of attention, working memory, mood, and personality assessment. Group differences in mean performance and variability were examined using Bayesian mixed effects location scale models. Variability in attention decreased from younger to older adults and then increased again in cognitive impairment. Younger adults were more variable in agreeableness, openness and conscientiousness compared to older adults. The clinically impaired group differed from the healthy older adults in terms of variability on attention, openness, and conscientiousness. Healthy aging results in greater stability in personality traits over short intervals yet this stability is not redundant with increased stability in cognitive scores.

Explorative behavior allows the successful finding of ephemeral food resources in the wild

AbstractThe repeatable among-individual variation in behavior (animal personality) is considered to affect fitness. The variation in personality traits is shaped by complex evolutionary mechanisms involving energy allocation and resource acquisition. However, an association between personality and individual performance in energy gain in the natural environment still seems underexplored. The aim of our study was to test a hypothesis that consistent individual variation in behavior affects the energy acquisition of unpredictable food resources. We predicted that more explorative individuals would be finding ephemeral food resources with higher probability than those less explorative. The quasi-experiment with ‘random-walking-feeders’ was performed to assess the use of unpredictable food resources in the natural habitat occupied by free-ranging arboreal rodents — edible dormice Glis glis. A repeated open field test at laboratory conditions was conducted to assess whether male dormice show consistent among-individual variation in behavior. The open field test analysis indicated two main components of dormice behavior: exploration and boldness, from which only the first one was repeatable and thus considered as a component of animal personality. The probability of finding a feeder increased with exploration, independently of dormice age and body size. The results indicate that exploration can be considered an adaptive trait that improves energy acquisition. We suggest that the behavioral among-individual variation within populations persists due to the usage of distinct foraging strategies in the face of fluctuations in food resources availability.

The impact of big five personality trait in predicting student academic performance

PurposeThe study aims to propose a predictive model that combines personality and demographic factors to predict student academic performance (SAP). This research study works on understanding, enhancing and applying techniques to enhance the prediction of SAP.Design/methodology/approachThe authors gathered information from 305 university students from Al-Zintan University Libya. The study uses a survey questionnaire to collect data on essential variables. The purpose of the questionnaire is to discover variables that affect students' academic performance. The survey questionnaire has 44 closed questions with Likert scale designs that were distributed to a variety of college students at the start of the first semester of 2022. It includes questions about demographics, personality, employment and institutional aspects. The authors proposed a predictive model to identify the main fundamental components, consisting of one dependent variable (SAP) and five independent constructs. The suggested model is tested using partial least squares (PLS) and structural equation modeling (SEM), which perform better than covariance-based structural equation modeling (CB-SEM). PLS-SEM performs well with smaller sample sizes, even for complicated models.FindingsThe study results show that the proposed model accurately predicted the student's academic performance. The personality trait variables are a key factor that determines the actual student's academic performance. The student's academic performance is significantly impacted by each variable in the personality trait variables as well.Originality/valueThe process of validating research was done empirically through the accuracy and efficiency of model performance. The study differs from previous studies in that it accumulated a wide range of factors from different dimensions, including student demographics and personality trait factors. The authors developed a structural equation model to predict students' academic performance.

Assessment of Personality Traits among Pediatric Dentists in India: A Cross-sectional Study.

To identify the most common personality traits among pediatric dentists in India. A cross-sectional study was conducted using the Big Five personality test (BFPT). It included 50 questions based on five personality traits-extroversion, agreeableness, conscientiousness, emotional stability, and openness to experience. The questionnaire was e-mailed and also sent through WhatsApp messages as a Google Form to all the pediatric dentists in India. Scoring for each trait was done based on the specific formula provided. The data were subjected to statistical analysis using Mann-Whitney U test. A total of 390 pediatric dentists responded and filled out the questionnaire. The agreeableness trait was the most commonly exhibited trait, followed by the conscientiousness trait. Emotional stability was the least exhibited trait. Emotional stability was statistically different between male and female pediatric dentists. Agreeableness and emotional stability were the most and least expressed traits, respectively, among the participants. This survey showed that pediatric dentists in India could have a high tolerance and competent behavior. Dentists may possess unique personality traits that distinguish them from the general population. Within the dental profession, there could be variations in personality traits depending on the specialty they practice. Asokan S, PR G, Dhanabalan O, et al. Assessment of Personality Traits Among Pediatric Dentists in India: A Cross-sectional Study. Int J Clin Pediatr Dent 2023;16(3):489-493.

Temperament and character in an Australian sample: examining cross-sectional associations of personality with age, sex, and satisfaction with life.

Personality can influence how we interpret and react to our day-to-day life circumstances. Temperament and character are the primary dimensions of personality, and both are influenced genetically. Temperament represents our emotional core, while character reflects our goals and values as we develop through life. Research shows that where people live, their social, economic, and physical environment can influence attitudes and behaviors, and these have links to variations in personality traits. There are few studies that focus on Australian personality as temperament and character. Using an Australian general population sample, we examined the psychometric properties of the Temperament and Character Inventory (TCIR140) and investigated the associations between TCIR140 traits with both sociodemographic variables and measures of well-being. In addition, we investigated differences in temperament and character between our Australian general population sample and published results of similar studies from other countries. Australians (N=1,510) completed the Temperament and Character Inventory (TCIR-140), the Positive and Negative Affect Scale and the Satisfaction with Life Scale. Cronbach's alpha and confirmatory factor analysis (CFA) examined the TCIR-140 psychometrics. Correlation analyzes, independent sample t-tests and ANOVA with post-hoc comparisons analyzed the sample. Cronbach's alphas were high, ranging from α=0.78-0.92, and the CFA confirmed two constructs of temperament and character. Females were higher in Harm Avoidance (p<0.001), Reward Dependence (p<0.001), and Cooperativeness (p<0.001) compared to males, who were higher in Self-Directedness (p<0.001). Age groups showed significant differences among all temperament and character traits (p<0.001) except for Reward Dependence (p=0.690). Young adults had the least resilient personality profile and poorest measures of well-being. Correlations with measures of temperament and character, well-being and affect were all in the expected direction. Temperament and character are related to indicators of wellbeing and differs by age and sex. This Australian sample demonstrate a temperament that is high in Persistence and a character high in Self-Directedness and Cooperativeness with an overall postive affect and a general satisfaction with life. In comparison to other countries, Australians in this sample differ in levels of several traits, demonstrating a cautious and independent temperament with a character that is cooperative, industrious, and self-reliant. Young-adults in comparison to older groups have a temperament and character profile that is prone to negative emotions and a lower satisfaction with life.

Examining individual differences in personality trait changes after negative life events

Personality traits can change throughout the entire life span, but people differ in their personality trait changes. To better understand individual differences in personality changes, we examined personal (personality functioning), environmental (environmental changes), and event-related moderators (e.g., perceived event characteristics) of personality trait changes. Therefore, we used a sample of 1069 participants who experienced a negative life event in the last 5 weeks and assessed their personality traits at five measurement occasions over 6 months. Employing preregistered multilevel lasso estimation, we did not find any significant effects. While exploratory analyses generally confirmed this conclusion, they also identified some effects that might being worth to be considered in future research (e.g., perceived impact and perceived social status changes were associated with changes in agreeableness after experiencing a relationship breakup). In total, our moderators explained less than 2% of variance in personality traits. Nonetheless, our study has several important implications for future research on individual differences in personality change. For example, future research should consider personal, environmental, and event-related moderators, use different analytical methods, and rely on highly powered samples to detect very small effects.

The Role of Personality Traits, Personality Functioning, Traumatic Life Events, and Emotion-Regulation Difficulties in Predicting Polysubstance Use

Objective: Polysubstance use as a severity index in individuals with substance abuse disorder is associated with various psychological, social, cultural, and genetic factors. This research aims to examine the predictive role of personality traits, personality functions, traumatic life events, and emotion-regulation difficulties in polysubstance use and the severity of dependence. Methods: A total of 300 subjects (75.2% male) with the mean age of 40.07 years and standard deviation of 12.26 were chosen via the available sampling method. The subjects included individuals abusing one substance (30.6%), a group abusing multiple substances (37.5%), and a nonclinical group (31.7%). The participants completed the questionnaires of short-form personality inventory based on The Diagnostic and Statistical Manual of Mental Disorders, fifth edition, levels of personality functioning scale, dysfunctional emotion regulation scale, and life events checklist. Results: The results of ranked regression and structural equation modeling indicated that the variables of personality traits (2.69), emotional regulation strategies (2.04), personality functioning (1.17), and stressful factors (1.65) had a significant role in predicting drug abuse. Conclusion: Personality affects all life dimensions. Emotion regulation strategies, by affecting maladaptive traits, especially negative affectivity and antagonism, as well as personality functions can predispose the person to polysubstance use.