Indicators Of Individual Differences Research Articles

Analysis of the tendency to select the “neither nor” option in agreement/disagreement scales on a low – salience topic: The contribution of individual differences

This paper examines the frequency of midpoint responses in agree/disagree scales in a survey measuring attitudes toward science and scientific policy, a low-salience and difficult topic. It also examines the contribution of individual differences to explain the tendency to select this option. It is assumed that the use of the midpoint “Neither agree nor disagree” (NA/ND) in Agree/Disagree (A/D) scales is to some extent an indication of satisficing. It is also assumed that there are individual differences in respondents’ tendency to select the NA/ND response. Using a Generalized Linear Mixed Model we include Krosnick’s regulators of satisficing, socio-demographics and individual differences as predictors. We find that the contribution of the regulators of satisficing identified by Krosnick is small. In turn, factors associated with individual differences explain a great amount of variance on the number of NA/ND responses. We conclude that the presence of this option in a survey of a low-salience topic increases satisficing as strategy of the respondents to deal with the cognitive burden of both the A/D scale and the difficulty of the topic. Furthermore, the number of NA/ND responses may be understood as an indicator of individual differences in the propensity of respondents to satisficing when answering a survey on a low-salience or difficult topic.

Individual differences in latent trait cortisol (LTC): Implications for the onset and course of future depressive symptoms

Research suggests that various indicators of hypothalamic pituitary adrenal (HPA) axis activity prospectively predict depression, but few studies have evaluated whether trait indicators of HPA axis activity are related to depression. Further, no prior study has examined links between trait cortisol and psychopathology using a trait indicator that captures HPA axis activity over multiple time points. Here we examined whether we could construct an across-wave latent trait cortisol (LTC) factor using cortisol samples collected over 13 weeks, and whether the across-wave LTC prospectively predicted new depressive symptom onsets and symptom duration. Emerging adults (n = 85; M age = 19.37 years) provided salivary cortisol samples four times a day (waking, 30 min and 45 min post-waking and bedtime) over three 3-day measurement waves separated by 6 weeks. Diagnostic interviews at 3 timepoints (baseline, 1- and 2.5 years post-baseline) assessed lifetime and current depressive symptoms. Results indicated that the across-wave LTC predicted new onsets of depressive symptoms and longer symptom duration. Follow-up tests revealed that the link between the across-wave LTC and new onsets was not significant after adjusting for past depressive symptoms. These findings suggest that an indicator of individual differences in HPA axis regulation has implications for depressive symptom onsets and course.

Measuring Comprehension Monitoring with the Inconsistency Task in Adolescents: Stability, Associations with Reading Comprehension Skills, and Differences Between Grade Levels

ABSTRACT The inconsistency task is used to measure metacognitive monitoring in text comprehension via online (reading time) and offline measures (number of detected inconsistencies). Few studies have examined stability in task performance and interindividual differences. We addressed these issues with adolescents (N = 341) in Grades 6/7 (Ma ge = 12.02 years) and 8/9 (M age = 14.07 years) at two measurement points and with expository texts. Performance in the offline and online measures were quite stable over one year with lower stability in the online measure. The two measures were only weakly associated. Only the offline measure was related to reading comprehension skills. Older (vs. younger) students performed better in the offline measure. The effect of grade level on the offline measure was mediated by intelligence and working memory capacity. Thus, the offline measure seems to be a better indicator of individual differences in comprehension monitoring in secondary school.

Treating random effects as observed versus latent predictors: The bias-variance tradeoff in small samples.

Random effects in longitudinal multilevel models represent individuals' deviations from population means and are indicators of individual differences. Researchers are often interested in examining how these random effects predict outcome variables that vary across individuals. This can be done via a two-step approach in which empirical Bayes (EB) estimates of the random effects are extracted and then treated as observed predictor variables in follow-up regression analyses. This approach ignores the unreliability of EB estimates, leading to underestimation of regression coefficients. As such, previous studies have recommended a multilevel structural equationmodeling (ML-SEM) approach that treats random effects as latent variables. The current study uses simulation and empirical data to show that a bias-variance tradeoff exists when selecting between the two approaches. ML-SEM produces generally unbiased regression coefficient estimates but also larger standard errors, which can lead to lower power than the two-step approach. Implications of the results for model selection and alternative solutions are discussed.

A study of second to fourth digit ratio in relation to verbal and numerical intelligence among medical students

Introduction and Aim: Prenatal androgens are believed to be one of the probable etiological factors influencing intellectual development of an individual. In-utero testosterone exposure has been thought to affect the digit ratio which is the ratio of lengths of index finger and ring finger (2D:4D). In the present work we intended to study the correlation of 2D:4D with numerical and verbal intelligence believed to be variable among genders. The aim of our study was to find the association of 2D:4D with Verbal Intelligence and Numerical Intelligence in a sample of medical students.
 
 Materials and Methods: This study was conducted in a sample of medical students. 44 female and 44 male students participated in the study. 2D:4D measurements were made using standard procedure after which the participants completed a questionnaire containing 20 questions each to test numerical and verbal intelligence.
 
 Results: In this study, Males were found to have a lower 2D:4D when compared to females. Individuals with lower 2D:4D in their right-hand were seen to have lower verbal intelligence and higher numerical intelligence thus suggesting that males are born with better numerical intelligence and females with greater verbal intelligence.
 
 Conclusion: Digit ratio can be considered as a valuable indicator of individual differences in terms of intelligence, although the exact role of testosterone on brain to cause variation in these cognitive domains is yet to be clearly understood.

An external telemetry system for recording resting heart rate variability and heart rate in free-ranging large wild mammals.

Measures of heart rate variability (and heart rate more generally) are providing powerful insights into the physiological drivers of behaviour. Resting heart rate variability (HRV) can be used as an indicator of individual differences in temperament and reactivity to physical and psychological stress. There is increasing interest in deriving such measures from free ranging wild animals, where individuals are exposed to the natural and anthropogenic stressors of life. We describe a robust, externally mounted heart rate monitor for use in wild mammals, deployed here on wild breeding adult female grey seals (Halichoerus grypus), that delivers millisecond precise measures of inter beat intervals (IBIs), allowing computation of resting HRV parameters. Based on Firstbeat™ heart rate belts, our system allows for remote, continuous recording of IBI data from over 30 individuals simultaneously at ranges of up to 200m. We assessed the accuracy of the IBI data provided by the Firstbeat™ system using concurrent IBI data derived from in-field electrocardiogram (ECG) recordings. Bland-Altmann analyses demonstrated high correspondence between the two sets of IBI data, with a mean difference of 0.87±0.16ms. We used generalized additive mixed-effects models to examine the impact of the default Firstbeat™ software artefact correction procedure upon the generation of anomalous data (flats and stairs). Artefact correction and individual activity were major causes of flats and stairs. We used simulations and models to assess the impact of these errors on estimates of resting HRV and to inform criteria for subsampling relatively error free IBI traces. These analyses allowed us to establish stringent filtering procedures to remove traces with excessive numbers of artefacts, including flats and stairs. Even with strict criteria for removing potentially erroneous data, the abundance of data yielded by the Firstbeat™ system provides the potential to extract robust estimates of resting HRV. We discuss the advantages and limitations of our system for applications beyond the study system described here.

Overestimating Self-Blame for Stressful Life Events and Adolescents' Latent Trait Cortisol: The Moderating Role of Parental Warmth.

Cognitive interpretations of stressful events impact their implications for physiological stress processes. However, whether such interpretations are related to trait cortisol-an indicator of individual differences in stress physiology-is unknown. In 112 early adolescent girls (M age = 12.39 years), this study examined the association between self-blame estimates for past year events and latent trait cortisol, and whether maternal warmth moderated effects. Overestimating self-blame (versus objective indices) for independent (uncontrollable) events was associated with lower latent trait cortisol, and maternal warmth moderated the effect of self-blame estimates on latent trait cortisol for each dependent (at least partially controllable) and interpersonal events. Implications for understanding the impact of cognitive and interpersonal factors on trait cortisol during early adolescence are discussed.

The Relationship Between Resting State Network Connectivity and Individual Differences in Executive Functions.

The brain is organized into a number of large networks based on shared function, for example, high-level cognitive functions (frontoparietal network), attentional capabilities (dorsal and ventral attention networks), and internal mentation (default network). The correlations of these networks during resting-state fMRI scans varies across individuals and is an indicator of individual differences in ability. Prior work shows higher cognitive functioning (as measured by working memory and attention tasks) is associated with stronger negative correlations between frontoparietal/attention and default networks, suggesting that increased ability may depend upon the diverging activation of networks with contrasting function. However, these prior studies lack specificity with regard to the higher-level cognitive functions involved, particularly with regards to separable components of executive function (EF). Here we decompose EF into three factors from the unity/diversity model of EFs: Common EF, Shifting-specific EF, and Updating-specific EF, measuring each via factor scores derived from a battery of behavioral tasks completed by 250 adult participants (age 28) at the time of a resting-state scan. We found the hypothesized segregated pattern only for Shifting-specific EF. Specifically, after accounting for one’s general EF ability (Common EF), individuals better able to fluidly switch between task sets have a stronger negative correlation between the ventral attention network and the default network. We also report non-predicted novel findings in that individuals with higher Shifting-specific abilities exhibited more positive connectivity between frontoparietal and visual networks, while those individuals with higher Common EF exhibited increased connectivity between sensory and default networks. Overall, these results reveal a new degree of specificity with regard to connectivity/EF relationships.

Socially desirable responding suppresses the association between self-assessed intelligence and task-based intelligence

The response bias hypothesis specifies that the predictive capacity of a predictor should be enhanced by controlling for the effects of bias on the predictor variable, in particular, socially desirable responding (SDR) bias. To-date, the vast majority of the SDR research in the area, which is principally personality related, has failed to support the response bias hypothesis, as SDR suppressor effects have not been observed. Consequently, it has been contended that SDR is not a problem for self-report measurement, that SDR measures may themselves be indicators of trait variance, and that it was likely impossible to determine whether an elevated SDR score reflected a trait or response bias. However, in contrast to personality, intelligence is an area within which comparisons between subjective scores (self-reported) and objective scores (task-based) can be made. Consequently, the purpose of this investigation was to test the response bias hypothesis (N = 253) with self-report measures of intellectual and emotional intelligence (SRIQ and SREI) and task-based measures of intellectual and emotional intelligence (TBIQ and TBEI), in conjunction with a multi-dimensional measure of SDR (Balanced Inventory of Desirable Responding; BIDR). The percentage of variance accounted for in TBIQ by SRIQ, and in TBEI by SREI, increased by 1% and 2.1%, respectively, when SDR was included in the model. The 1% to 2.1% increases in criterion (concurrent) validity were interpreted as practically significant, based on previously published simulation work. Finally, it was concluded that self-report measures may be non-negligibly influenced by individual differences in SDR, and that the BIDR may possess some validity as an indicator of individual differences in socially desirable responding.

English

Due to the critical role that perceptual learning styles as indicators of individual differences play in L2 learners' activities and thus their academic achievement, the present investigation was aimed to study the role of L2 learners' perceptual styles in lexical inferencing and also the strategies used for lexical inferences in the Iranian context of English language learning. To this end, 134 participants majoring in different engineering fields took part in the study. They received strategy training on how to infer the meanings of unfamiliar words. They then answered a perceptual styles preferences questionnaire and were tested on the selected texts for lexical inferencing. They were asked to extract the meaning of unfamiliar words and simultaneously identify the relevant strategy employed for lexical inferencing by marking it on the strategy questionnaire. The analysis identified the biggest number of participants as being kinesthetic despite the fact that classes were mainly held through audio-visual activities. The findings also showed a meaningful difference between group categories of styles preferences and their lexical inferencing ability (F=4.57, p<.05). As for the modifying effect of perceptual styles on the strategies used by various groups of learners, 'visual learners' were found to have the highest correlation with ‘syntactic knowledge analysis’ (r=.70, p=.01). The results of the study point to the importance of individual differences in the perception of and interaction with the learning environment. Keywords: perceptual learning styles; lexical inferencing; strategy training; strategy use; L2 DOI: http://doi.org/10.17576/3L-2016-2201-14

Women's attachment as a predictor of pain during labour and post-delivery: a prospective observational study.

Labour is considered to be one of the most painful and significant experiences in a woman's life. The aim of this study was to examine whether women's attachment style is a predictor of the pain experienced throughout labour and post-delivery. Thirty-two pregnant women were assessed during the third trimester of pregnancy and during labour. Adult attachment was assessed with the Adult Attachment Scale ' Revised. The perceived intensity of labour pain was measured using a visual analogue scale for pain in the early stage of labour, throughout labour and post-delivery. Women with an insecure attachment style reported more pain at 3 cm of cervical dilatation (p &lt; 0.05), before the administration of analgesia (p &lt; 0.01) and post-delivery (p &lt; 0.05) than those securely attached. In multivariate models, attachment style was a significant predictor of labour pain at 3 cm of cervical dilatation and before the first administration of analgesia but not of the perceived pain post-delivery. These findings confirm that labour pain is influenced by relevant psychological factors and suggest that a woman's attachment style may be a risk factor for greater pain during labour. Future studies in the context of obstetric pain may consider the attachment style as an indicator of individual differences in the pain response during labour. This may have important implications in anaesthesiology and to promote a relevant shift in institutional practices and therapeutic procedures.

Measuring Developmental Differences With an Age-of-Attainment Method

The sensitive measurement of variation in rate of attainment is an underutilized but useful indicator of individual differences in development. To assess such individuality, we used longitudinal parental diary checklists of infant attainments to estimate the ages at which ubiquitous developmental milestones like sitting and walking were reached. Parents using this diary checklist have been shown to be valid reporters of milestone attainments. Present analyses show that multiple definitions of milestone onset have high reliability as well. Babies differ considerably in their rates of development, and such individual differences in rates may be predicted from other variables with survival (event history) analysis. Ages of attainment for sustained sitting, crawling, and walking were calculated for 519 infants and predicted using 11 common covariates. Our discovery that babies of younger mothers reach these milestones sooner than those of older mothers reveals the value of an age-of-attainment (AOA) approach. A framework with a SAS program for collecting and analyzing AOA data is presented.

Implicit self-esteem in the context of trait models of personality

Although the basic dimensions of personality are strongly associated with individual differences in (explicit) self-esteem, the relations between personality and implicit self-esteem have not been systematically researched. In three studies, implicit self-evaluations (measured both with the Name-Letter Test and the self-esteem IAT) were generally independent of personality self-reports (Studies 1–3) and peer-reports (Study 3). Moreover, the implicit measures were also independent of one another. Discussion centers on the problems and promises of implicit measures as indicators of individual differences in self-esteem and their relation to personality.

Genetic effects on task performance, but not on age polyethism, in a swarm-founding eusocial wasp

Division of labour among workers in insect societies often includes two major components: age-related changes in behaviour (age polyethism) and specialization in task performance. The aim of this study was to test whether similarity in inside-nest task performance and in rate of age polyethism correspond to genetic similarity among nestmates in the polygynous eusocial waspPolybia aequatorialis.Behavioural data were collected on marked, known-age workers from three source colonies introduced into two observation colonies in the field. Genetic similarity among workers was assessed by quantifying sharing of random amplified polymorphic DNA (RAPD) marker alleles. Workers were categorized by whether they engaged in nest cleaning as an indicator of individual differences in inside-nest task performance. Within source colonies, workers that performed nest-cleaning tasks were more genetically similar to each other than they were to workers not performing these tasks. Workers also differed in their rates of passage through the age-related task sequence, but no association was found between sharing of RAPD marker alleles and rate of age polyethism. These results accord with earlier studies demonstrating flexibility in age polyethism in swarm-founding wasps, and with findings that worker genotypic variability corresponds to specialization in task performance inP. aequatorialis. Polybiaspp. workers rarely switch among tasks, even in response to changes in colony conditions, and workers’ genotypes may constrain flexibility in task performance at the individual level. Conversely, colonies may accrue benefits from having genotypically diverse worker forces, which could favour the maintenance of polygyny in swarm-founding wasps.

Research Evidence regarding the Validity and Effects of Talent Search Educational Programs

In this paper we review evidence regarding the validity of educational programs based on the talent search identification protocol and their effects on students. Research shows that talent search scores are valid indicators of students who can succeed in courses that are accelerated in terms of content and learning pace. SAT scores at the junior high level predict achievement in high school and college and are valid indicators of individual differences within the gifted and talented population. Talent search students who partake of special summer or accelerated school programs are more likely to take a more rigorous course of study in high school and attend more selective colleges. Effects may be especially potent for academically talented females who pursue mathematics in summer programs.

Event-related-potential (ERP) correlates of cognitive styles, abilities and aptitudes

Fifty, right-handed males were given 11 psychometric tests of cognitive styles, abilities and aptitudes. Visual (VERP), auditory (AERP) and bimodal (BERP) brain event-related-potential (ERP) amplitudes were recorded from each of these Ss. Canonical and product-moment correlations were computed. These analyses established that VERPs and BERPs elicited in the frontal, temporal, parietal and occipital regions were related to abilities and aptitudes: general aptitude, reading and verbal comprehension and spatial ability; and a cognitive style: field dependence-independence. The results demonstrated the construct validity of ERPs as indicators of individual differences in cognitive characteristics, especially crystallized and fluid intelligence.

Individual differences in noise and associated perceptual indices of performance.

Vickers et al. (1972) proposed that three main determinants of perceptual organization are the inspection time λ governing the rate of accumulation of sensory data, the noise in the visual system sD, and the degree of caution adopted for responding. The mean overall latency of judgments in a simple psychophysical discrimination task L was suggested to provide a satisfactory indirect index of caution. Differences between individuals in these three behavioural descriptors, together with an index of the use made of immediate memory δ, were compared with personality measured by the Manifest Anxiety Scale and the Eysenck Personality Inventory. Results from two experiments confirmed the independence of λ, sD, L, and δ as indicators of individual differences. The relationships between these measures and scores on the personality scales were clear, but not always straightforward. They are examined in terms of interactions between the processes underlying the measures.

Analysis of the Chunked Reading Test and Reading Comprehension

The newly developed Chunked Reading Test was further analyzed by correlating the scores on this test with three other standardized reading tests—Davis Reading Test, Nelson-Denny Reading Test, and Tinker Speed of Reading Test. A rational analysis of the scores on all of the tests suggested that each score could be designated as measuring one of the following three types of variables: efficiency (E), accuracy (A), and rate (R). The tests were administered to 41 college students and the inter-correlations were factor analyzed. Two factors fit the data, and they were readily interpretable as an A factor and an R factor. A single factor fit forced upon the data was readily interpretable as an E factor. The results suggested that: (a) apparent differences among the variables measured by standardized reading tests for adults are more superficial than real, (b) all of the scores on these tests can be interpreted as being valid indicators of individual differences in the efficiency, accuracy, and rate at which thoughts are understood while reading, and (c) empirical support exists for the purported theoretical relationship, E=AR.

An Eye-Movement Indicator of Individual Differences in the Physiological Organization of Attentional Processes and Anxiety

An Eye-Movement Indicator of Individual Differences in the Physiological Organization of Attentional Processes and Anxiety