The validity of the multi-informant approach to assessing child and adolescent mental health

Child and adolescent patients may display mental health concerns within some contexts and not others (e.g., home vs. school). Thus, understanding the specific contexts in which patients display concerns may assist mental health professionals in tailoring treatments to patients' needs. Consequently, clinical assessments often include reports from multiple informants who vary in the contexts in which they observe patients' behavior (e.g., patients, parents, teachers). Previous meta-analyses indicate that informants' reports correlate at low-to-moderate magnitudes. However, is it valid to interpret low correspondence among reports as indicating that patients display concerns in some contexts and not others? We meta-analyzed 341 studies published between 1989 and 2014 that reported cross-informant correspondence estimates, and observed low-to-moderate correspondence (mean internalizing: r = .25; mean externalizing: r = .30; mean overall: r = .28). Informant pair, mental health domain, and measurement method moderated magnitudes of correspondence. These robust findings have informed the development of concepts for interpreting multi-informant assessments, allowing researchers to draw specific predictions about the incremental and construct validity of these assessments. In turn, we critically evaluated research on the incremental and construct validity of the multi-informant approach to clinical child and adolescent assessment. In so doing, we identify crucial gaps in knowledge for future research, and provide recommendations for "best practices" in using and interpreting multi-informant assessments in clinical work and research. This article has important implications for developing personalized approaches to clinical assessment, with the goal of informing techniques for tailoring treatments to target the specific contexts where patients display concerns. (PsycINFO Database Record

Toward a model of drug relapse: an assessment of the validity of the reinstatement procedure

BACKGROUND AND RATIONALE

The reinstatement model is widely used to study relapse to drug addiction. However, the model's validity is open to question.

OBJECTIVE

We assess the reinstatement model in terms of criterion and construct validity.

RESEARCH HIGHLIGHTS AND CONCLUSIONS

We find that the reinstatement model has adequate criterion validity in the broad sense of the term, as evidenced by the fact that reinstatement in laboratory animals is induced by conditions reported to provoke relapse in humans. The model's criterion validity in the narrower sense, as a medication screen, seems promising for relapse to heroin, nicotine, and alcohol. For relapse to cocaine, criterion validity has not yet been established primarily because clinical studies have examined medication's effects on reductions in cocaine intake rather than relapse during abstinence. The model's construct validity faces more substantial challenges and is yet to be established, but we argue that some of the criticisms of the model in this regard may have been overstated.

The attack of the psychometricians

This paper analyzes the theoretical, pragmatic, and substantive factors that have hampered the integration between psychology and psychometrics. Theoretical factors include the operationalist mode of thinking which is common throughout psychology, the dominance of classical test theory, and the use of "construct validity" as a catch-all category for a range of challenging psychometric problems. Pragmatic factors include the lack of interest in mathematically precise thinking in psychology, inadequate representation of psychometric modeling in major statistics programs, and insufficient mathematical training in the psychological curriculum. Substantive factors relate to the absence of psychological theories that are sufficiently strong to motivate the structure of psychometric models. Following the identification of these problems, a number of promising recent developments are discussed, and suggestions are made to further the integration of psychology and psychometrics.

Estimating facets of psychopathy from normal personality traits: a step toward community epidemiological investigations

In three samples consisting of community and undergraduate men and women and incarcerated men, we examined the criterion validity of two distinct factors of psychopathy embodied in the Psychopathic Personality Inventory (PPI) as indexed by primary trait scales from the Multidimensional Personality Questionnaire (MPQ). Consistent with the PPI factors themselves, MPQ-estimated PPI-I related negatively with internalizing disorder symptoms and fearfulness and positively with thrill and adventure seeking, sociability, activity, and narcissism. MPQ-estimated PPI-II was associated negatively with socialization and positively with externalizing disorder symptoms, impulsivity, disinhibition and boredom susceptibility, and trait anxiety and negative emotionality. Additionally, PPI-I was selectively related to the interpersonal facet of Factor 1 of the Psychopathy Checklist-Revised (PCL-R), whereas PPI-II was related preferentially to Factor 2 of the PCL-R.

Exploring the Validity of Valproic Acid Animal Model of Autism

The valproic acid (VPA) animal model of autism spectrum disorder (ASD) is one of the most widely used animal model in the field. Like any other disease models, it can't model the totality of the features seen in autism. Then, is it valid to model autism? This model demonstrates many of the structural and behavioral features that can be observed in individuals with autism. These similarities enable the model to define relevant pathways of developmental dysregulation resulting from environmental manipulation. The uncovering of these complex pathways resulted to the growing pool of potential therapeutic candidates addressing the core symptoms of ASD. Here, we summarize the validity points of VPA that may or may not qualify it as a valid animal model of ASD.

Treatment of schizophrenia negative symptoms: future prospects

New findings from neuroscience, genetics, and experimental psychology have emerged that provide alternative explanations of many negative symptoms. We review the continuing limitations in treatment and discuss possible sources of heterogeneity among negative symptoms. We also anticipate conceptual uncertainties that may arise with forthcoming treatment developments.

The psychometric property and validation of a fatalism scale

In this article, we conceptualised fatalism as a set of health beliefs that encompass the dimensions of predetermination, luck and pessimism. A 20-item scale was developed as a measurement instrument. Confirmatory factor analyses were performed to test the dimensionality of the scale. Three external variables (i.e. genetic determinism, perceived benefits of lifestyle change and intention to engage in healthy behaviour) were used as reference variables to test the construct validity of the scale. Data from a web-based national survey (N = 1218) showed that the scale was unidimensional on the second order, and with good reliability (alpha = 0.88). The relationships between the external variables and the first- and second-order factors provided evidence of the scale's external consistency and construct validity.

Construct validity of cognitive reserve in a multiethnic cohort: The Northern Manhattan Study

Cognitive reserve is a hypothetical construct that has been used to inform models of cognitive aging and is presumed to be indicative of life experiences that may mitigate the effects of brain pathology. The purpose of this study was to evaluate the construct validity of cognitive reserve by examining both its convergent and its discriminant validity across three different samples of participants using structural equation modeling. The cognitive reserve variables were found to correlate highly with one another (thereby providing evidence of convergent validity), but demanding tests of discriminant validity indicated that, in two of the samples, the cognitive reserve construct was highly related to an executive functioning construct.

Five-level emergency triage systems: variation in assessment of validity

INTRODUCTION

Triage systems are scales developed to rate the degree of urgency among patients who arrive at EDs. A number of different scales are in use; however, the way in which they have been validated is inconsistent. Also, it is difficult to define a surrogate that accurately predicts urgency. This systematic review described reference standards and measures used in previous validation studies of five-level triage systems.

METHODS

We searched PubMed, EMBASE and CINAHL to identify studies that had assessed the validity of five-level triage systems and described the reference standards and measures applied in these studies. Studies were divided into those using criterion validity (reference standards developed by expert panels or triage systems already in use) and those using construct validity (prognosis, costs and resource use).

RESULTS

A total of 57 studies examined criterion and construct validity of 14 five-level triage systems. Criterion validity was examined by evaluating (1) agreement between the assigned degree of urgency with objective standard criteria (12 studies), (2) overtriage and undertriage (9 studies) and (3) sensitivity and specificity of triage systems (7 studies). Construct validity was examined by looking at (4) the associations between the assigned degree of urgency and measures gauged in EDs (48 studies) and (5) the associations between the assigned degree of urgency and measures gauged after hospitalisation (13 studies). Particularly, among 46 validation studies of the most commonly used triages (Canadian Triage and Acuity Scale, Emergency Severity Index and Manchester Triage System), 13 and 39 studies examined criterion and construct validity, respectively.

CONCLUSION

Previous studies applied various reference standards and measures to validate five-level triage systems. They either created their own reference standard or used a combination of severity/resource measures.

Is it really self-control? Examining the predictive power of the delay of gratification task

This investigation tests whether the predictive power of the delay of gratification task (colloquially known as the "marshmallow test") derives from its assessment of self-control or of theoretically unrelated traits. Among 56 school-age children in Study 1, delay time was associated with concurrent teacher ratings of self-control and Big Five conscientiousness-but not with other personality traits, intelligence, or reward-related impulses. Likewise, among 966 preschool children in Study 2, delay time was consistently associated with concurrent parent and caregiver ratings of self-control but not with reward-related impulses. While delay time in Study 2 was also related to concurrently measured intelligence, predictive relations with academic, health, and social outcomes in adolescence were more consistently explained by ratings of effortful control. Collectively, these findings suggest that delay task performance may be influenced by extraneous traits, but its predictive power derives primarily from its assessment of self-control.

Development and validation of Triarchic construct scales from the psychopathic personality inventory

The Triarchic model of psychopathy describes this complex condition in terms of distinct phenotypic components of boldness, meanness, and disinhibition. Brief self-report scales designed specifically to index these psychopathy facets have thus far demonstrated promising construct validity. The present study sought to develop and validate scales for assessing facets of the Triarchic model using items from a well-validated existing measure of psychopathy-the Psychopathic Personality Inventory (PPI). A consensus-rating approach was used to identify PPI items relevant to each Triarchic facet, and the convergent and discriminant validity of the resulting PPI-based Triarchic scales were evaluated in relation to multiple criterion variables (i.e., other psychopathy inventories, antisocial personality disorder features, personality traits, psychosocial functioning) in offender and nonoffender samples. The PPI-based Triarchic scales showed good internal consistency and related to criterion variables in ways consistent with predictions based on the Triarchic model. Findings are discussed in terms of implications for conceptualization and assessment of psychopathy.

The hundred-year emotion war: are emotions natural kinds or psychological constructions? Comment on Lench, Flores, and Bench (2011)

For the last century, there has been a continuing debate about the nature of emotion. In the most recent offering in this scientific dialogue, Lench, Flores, and Bench (2011) reported a meta-analysis of emotion induction research and claimed support for the natural kind hypothesis that discrete emotions (e.g., happiness, sadness, anger, and anxiety) elicit specific changes in cognition, judgment, behavior, experience, and physiology. In this article, we point out that Lench et al. (2011) is not the final word on the emotion debate. First, we point out that Lench et al.'s findings do not support their claim that discrete emotions organize cognition, judgment, experience, and physiology because they did not demonstrate emotion-consistent and emotion-specific directional changes in these measurement domains. Second, we point out that Lench et al.'s findings are in fact consistent with the alternative (a psychological constructionist approach to emotion). We close by appealing for a construct validity approach to emotion research, which we hope will lead to greater consensus on the operationalization of the natural kind and psychological construction approaches, as well as the criteria required to finally resolve the emotion debate.

Construct validation of patient global impression of severity (PGI-S) and improvement (PGI-I) questionnaires in the treatment of men with lower urinary tract symptoms secondary to benign prostatic hyperplasia

BACKGROUND

Lower urinary tract symptoms (LUTS) in aging men are often associated with benign prostatic hyperplasia (BPH). While regulatory evaluations of treatment benefit require an assessment of specific symptoms, a simpler approach to measuring patients' perceptions of severity and symptom change may be particularly useful for clinical practice. The aim of this study was to provide evidence of the validity of the 1-item Patient Global Impression of Severity (PGI-S) and Improvement (PGI-I) questionnaires for use as outcome measures in the treatment of BPH-LUTS.

METHODS

This was a secondary analysis of data from 4 randomized placebo-controlled 12-week trials evaluating tadalafil for the treatment of BPH-LUTS (N=1694). Visit 2 (V2 [beginning of a 4-week placebo lead-in period]) and endpoint assessments included International Prostate Symptom Score (IPSS), IPSS Quality of Life Index (IPSS-QoL), BPH Impact Index (BII), and peak urine flow (Qmax). PGI-S was only administered at V2 and PGI-I only at endpoint. Associations between the PGI-S or the PGI-I and the other assessments were analyzed by calculating Spearman rank correlation coefficients and performing analysis of variance (ANOVA).

RESULTS

Spearman correlation coefficients were 0.43, 0.43, 0.53, and -0.09, between the PGI-S and IPSS, IPSS-QoL, BII, and Qmax baseline results (all P<0.001). Similar results were seen across race, ethnicity, and baseline severity (moderate LUTS versus severe LUTS). IPSS, IPSS-QoL, BII baseline scores (P <0.001) and Qmax values (P=0.003) were significantly different among the 4 PGI-S severity levels. Spearman correlation coefficients were 0.56, 0.53, 0.47 and -0.15 between the PGI-I and change in IPSS, IPSS-QoL, BII scores, and Qmax values from baseline to endpoint (all P<0.001). Similar results were seen across race, ethnicity, and baseline severity. Change in IPSS, IPSS-QoL, BII scores, and Qmax values (P<0.001) were significantly different among the PGI-I levels (i.e., patient perception of change in urinary symptoms).

CONCLUSIONS

This study demonstrated patients' overall perceptions of their severity and change in BPH-LUTS can be captured in a way that is simple, valid, and easily administered in a research setting or clinical practice. Clinical parameters are weakly associated with patients' perception of urinary symptoms, emphasizing the importance of a patient-reported assessment in the evaluation of BPH-LUTS treatment benefit.

Refinement and revalidation of the demoralization scale: The DS-II-external validity

BACKGROUND

The recently refined Demoralization Scale-II (DS-II) is a 16-item, self-report measure of demoralization. Its 2 factors-Meaning and Purpose and Distress and Coping Ability-demonstrate sound internal validity, including item fit, unidimensionality, internal consistency, and test-retest reliability. The convergent and discriminant validity of the DS-II with various measures is reported here.

METHODS

Patients who had cancer or other progressive diseases and were receiving palliative care (n = 211) completed a battery of questionnaires, including the DS-II and measures of symptom burden, quality of life, depression, and attitudes toward the end of life. Spearman ρ correlations were determined to assess convergent validity. Mann-Whitney U tests with calculated effect sizes were used to examine discriminant validity and establish the minimal clinically important difference (MCID). Cross-tabulation frequencies with chi-square analyses were used to examine discriminant validity with major depression.

RESULTS

The DS-II demonstrated convergent validity with measures of psychological distress, quality of life, and attitudes toward the end of life. It also demonstrated discriminant validity, as the DS-II differentiated patients who had different functional performance levels and high/low symptoms, with a difference of 2 points between groups on the DS-II considered clinically meaningful. Furthermore, discriminant validity was demonstrated, as comorbidity with depression was not observed at moderate levels of demoralization.

CONCLUSIONS

The DS-II has sound psychometric properties and is an appropriate measure of demoralization. Given its structural simplicity and brevity, it is likely to be a useful tool in meaning-centered therapies. Cancer 2016;122:2260-7. © 2016 American Cancer Society.

Factor structure, convergent validity, and discriminant validity of the NIH Toolbox Cognitive Health Battery (NIHTB-CHB) in adults

The objective of this study is to evaluate the construct validity of the NIH Neurobehavioral Toolbox Cognitive Health Battery (NIHTB-CHB) in adults. Confirmatory factor analysis was used to evaluate the dimensional structure underlying the NIHTB-CHB and Gold Standard tests chosen to serve as concurrent validity criteria for the NIHTB-CHB. These results were used to evaluate the convergent and discriminant validity of the NIHTB-CHB in adults ranging from 20 to 85 years of age. Five dimensions were found to explain the correlations among NIHTB-CHB and Gold Standard tests: Vocabulary, Reading, Episodic Memory, Working Memory and Executive Function/Processing Speed. NIHTB-CHB measures and their Gold Standard analogues defined factors in a pattern that broadly supported the convergent and discriminant validity of the NIHTB-CHB tests. This 5-factor structure was found to be invariant across 20-60 year old (N=159) and 65-85 year old (N=109) age groups that were included in the current validity study. Second order Crystallized Abilities (Vocabulary and Reading) and Fluid Abilities (Episodic Memory, Working Memory, Executive/Speed) factors parsimoniously explained correlations among the five first order factors. These results suggest that the NIHTB-CHB will provide both fine-grained and broad characterization of cognition across the adult age span.

Feasibility and construct validity of PROMIS and "legacy" instruments in an academic scleroderma clinic

OBJECTIVE

The National Institutes of Health Patient-Reported Outcomes Measurement Information System (PROMIS) roadmap initiative is a cooperative group program of research designed to develop, evaluate, and standardize item banks to measure patient-reported outcomes relevant across medical conditions. The objective of the current study was to assess feasibility and evaluation of the construct validity of PROMIS item banks versus legacy measures in an observational study in systemic sclerosis (SSc). We hypothesized that the PROMIS item banks can be administered in a clinical setting if there is adequate staff support without disrupting the flow of clinic.

METHODS

Patients with SSc in a single academic center completed computerized adaptive test (CAT) administered PROMIS item banks during the clinic visit and legacy measures (using paper and pencil). The construct validity of PROMIS items was evaluated by examining correlations with corresponding legacy measures using multitrait-multimethod analysis.

RESULTS

Participants consisted of 143 SSc patients with an average age of 51.5 years; 71% were female and 68% were white. The average number of items completed for each CAT-administered item bank ranged from 5 to 8 (69 CAT items per patient), and the average time to complete each CAT-administered item bank ranged from 48 seconds to 1.9 minutes per patient (average time = 11.9 minutes/per patient for 11 banks). All correlations between PROMIS domains and respective legacy measures were large and in the hypothesized direction (ranged from 0.61 to 0.82).

CONCLUSION

Our study supports the construct validity of the CAT-administered PROMIS item banks and shows that they can be administered successfully in a clinic with support staff. Future studies should assess the feasibility of PROMIS item banks in a busy clinical practice.

Animal models of amyotrophic lateral sclerosis: A comparison of model validity

Animal models are necessary to investigate the pathogenic features underlying motor neuron degeneration and for therapeutic development in amyotrophic lateral sclerosis (ALS). Measures of model validity allow for a critical interpretation of results from each model and caution from over-interpretation of experimental models. Face and construct validity refer to the similarity in phenotype and the proposed causal factor to the human disease, respectively. More recently developed models are restricted by limited phenotype characterization, yet new models hold promise for novel disease insights, thus highlighting their importance. In this article, we evaluate the features of face and construct validity of our new zebrafish model of environmentally-induced motor neuron degeneration and discuss this in the context of current environmental and genetic ALS models, including C9orf72, mutant Cu/Zn superoxide dismutase 1 and TAR DNA-binding protein 43 mouse and zebrafish models. In this mini-review, we discuss the pros and cons to validity criteria in each model. Our zebrafish model of environmentally-induced motor neuron degeneration displays convincing features of face validity with many hallmarks of ALS-like features, and weakness in construct validity. However, the value of this model may lie in its potential to be more representative of the pathogenic features underlying sporadic ALS cases, where environmental factors may be more likely to be involved in disease etiology than single dominant gene mutations. It may be necessary to compare findings between different strains and species modeling specific genes or environmental factors to confirm findings from ALS animal models and tease out arbitrary strain- and overexpression-specific effects.

Discriminant and convergent validity of the anxiety construct in children with autism spectrum disorders

Despite reports of high anxiety in children with autism spectrum disorders (ASD), there is controversy regarding differential diagnosis of ASD symptoms and anxiety symptoms. This study examined 88 children, aged 7-11 years, with ASD referred for concerns about anxiety. A multitrait-(social anxiety, separation anxiety, overall anxiety severity, and overall ASD severity), multimethod-(diagnostic interviews, parent-, and child-based measures) analysis was conducted. Results from structural equation modeling suggest statistical discrimination between anxiety and ASD severity and convergence among differing reports of two of the anxiety subdomains (separation anxiety and overall anxiety). These findings suggest that anxiety symptoms experienced by children with ASD are separate from ASD symptom severity and may instead reflect anxiety syndromes (e.g., separation anxiety) similar to those that occur in typically developing children.

The measurement of boredom: differences between existing self-report scales

There are two commonly used measures of boredom: the Boredom Proneness Scale (BPS) and the Boredom Susceptibility Scale (ZBS). Although both were designed to measure the propensity to experience boredom (i.e., trait boredom), there are reasons to think they may not measure the same construct. The present research sought to evaluate this proposition in several stages. Specifically, relationships between the BPS, ZBS, and important causal (Study 1, N = 837), correlational (Study 2, N = 233), and outcome variables (Study 3, N = 137) were examined in university students. Taken together, results support the notion that the BPS and ZBS do not measure the same construct. Specifically, higher BPS scores were associated with higher levels of neuroticism, experiential avoidance, attentional and nonplanning impulsivity, anxiety, depression, dysphoria, and emotional eating. Conversely, higher ZBS scores were associated with higher levels of motor impulsivity, sensitivity to reward, gambling, and alcohol use and lower levels of neuroticism, experiential avoidance, and sensitivity to punishment.

Expanding the Nomological Net of the Pathological Narcissism Inventory: German Validation and Extension in a Clinical Inpatient Sample

The Pathological Narcissism Inventory (PNI) is a multidimensional measure for assessing grandiose and vulnerable features in narcissistic pathology. The aim of the present research was to construct and validate a German translation of the PNI and to provide further information on the PNI's nomological net. Findings from a first study confirm the psychometric soundness of the PNI and replicate its seven-factor first-order structure. A second-order structure was also supported but with several equivalent models. A second study investigating associations with a broad range of measures ( DSM Axis I and II constructs, emotions, personality traits, interpersonal and dysfunctional behaviors, and well-being) supported the concurrent validity of the PNI. Discriminant validity with the Narcissistic Personality Inventory was also shown. Finally, in a third study an extension in a clinical inpatient sample provided further evidence that the PNI is a useful tool to assess the more pathological end of narcissism.

Psychometric properties of the Hospital Survey on Patient Safety Culture, HSOPSC, applied on a large Swedish health care sample

BACKGROUND

A Swedish version of the USA Agency for Healthcare Research and Quality "Hospital Survey on Patient Safety Culture" (S-HSOPSC) was developed to be used in both hospitals and primary care. Two new dimensions with two and four questions each were added as well as one outcome measure. This paper describes this Swedish version and an assessment of its psychometric properties which were tested on a large sample of responses from personnel in both hospital and primary care.

METHODS

The questionnaire was mainly administered in web form and 84215 forms were returned (response rate 60%) between 2009 and 2011. Eleven per cent of the responses came from primary care workers and 46% from hospital care workers. The psychometric properties were analyzed using both the total sample and the hospital and primary care subsamples by assessment of construct validity and internal consistency. Construct validity was assessed by confirmatory (CFA) and exploratory factor (EFA) analyses and internal consistency was established by Cronbachs's α.

RESULTS

CFA of the total, hospital and primary care samples generally showed a good fit while the EFA pointed towards a 9-factor model in all samples instead of the 14-dimension S-HSOPSC instrument. Internal consistency was acceptable with Cronbach's α values above 0.7 in a major part of the dimensions.

CONCLUSIONS

The S-HSOPSC, consisting of 14 dimensions, 48 items and 3 single-item outcome measures, is used both in hospitals and in primary care settings in Sweden for different purposes. This version of the original American instrument has acceptable construct validity and internal consistency when tested on large datasets of first-time responders from both hospitals and primary care centres. One common instrument for measurements of patient safety culture in both hospitals and primary care settings is an advantage since it enables comparisons between sectors and assessments of national patient safety improvement programs. Future research into this version of the instrument includes comparing results from patient safety culture measurements with other outcomes in relation to safety improvement strategies.

Validation of the Impostor Phenomenon among Managers

Following up on earlier investigations, the present research aims at validating the construct impostor phenomenon by taking other personality correlates into account and to examine whether the impostor phenomenon is a construct in its own right. In addition, gender effects as well as associations with dispositional working styles and strain are examined. In an online study we surveyed a sample of N = 242 individuals occupying leadership positions in different sectors. Confirmatory factor analyses provide empirical evidence for the discriminant validity of the impostor phenomenon. In accord with earlier studies we show that the impostor phenomenon is accompanied by higher levels of anxiety, dysphoric moods, emotional instability, a generally negative self-evaluation, and perfectionism. The study does not reveal any gender differences concerning the impostor phenomenon. With respect to working styles, persons with an impostor self-concept tend to show perfectionist as well as procrastinating behaviors. Moreover, they report being more stressed and strained by their work. In sum, the findings show that the impostor phenomenon constitutes a dysfunctional personality style. Practical implications are discussed.

Comparative psychometrics: establishing what differs is central to understanding what evolves

Cognitive abilities cannot be measured directly. What we can measure is individual variation in task performance. In this paper, we first make the case for why we should be interested in mapping individual differences in task performance onto particular cognitive abilities: we suggest that it is crucial for examining the causes and consequences of variation both within and between species. As a case study, we examine whether multiple measures of inhibitory control for non-human animals do indeed produce correlated task performance; however, no clear pattern emerges that would support the notion of a common cognitive ability underpinning individual differences in performance. We advocate a psychometric approach involving a three-step programme to make theoretical and empirical progress: first, we need tasks that reveal signature limits in performance. Second, we need to assess the reliability of individual differences in task performance. Third, multi-trait multi-method test batteries will be instrumental in validating cognitive abilities. Together, these steps will help us to establish what varies between individuals that could impact their fitness and ultimately shape the course of the evolution of animal minds. Finally, we propose executive functions, including working memory, inhibitory control and attentional shifting, as a sensible starting point for this endeavour.This article is part of the theme issue 'Causes and consequences of individual differences in cognitive abilities'.