The many foibles of Likert scales challenge claims that self-report measures of self-control are better than performance-based measures.

Self-control and executive functioning are often treated as highly related psychological constructs. However, measures of each rarely correlate with one another. This reflects some combination of true separability between the constructs and measurement differences. Traditionally, executive functioning is objectively measured as performance on computer-controlled tasks in the laboratory, whereas self-control is subjectively measured with self-report scales of predispositions and behaviors in everyday life. Self-report measures tend to better predict outcomes that should be affected by individual differences in control. Our two studies show that the original version of Tangney, Baumeister, and Boone's brief self-control scale (consisting of four positive and nine negative items) strongly correlates with self-esteem, mental health, fluid intelligence, but only weakly with satisfaction with life and happiness. Four variants of the original scale were created by reverse-wording the 13 original items and recombining them to form, for example, versions with all positive or all negative items. As the proportion of items with positive valence increased: (1) the outcomes with strong correlations in the original scale weakened and the weak correlations strengthened and (2) the mean overall scores increased. Both studies replicated a common finding that the original scale yields two factors in an exploratory factor analysis. However, the second factor is generated by method differences, namely, having items with both positive and negative valence. The second factor is induced by the common practice of reverse-coding the items with negative valence and the faulty assumption that Likert scales are equal-interval scales with a neutral-point at midscale.

There is no coherent evidence for a bilingual advantage in executive processing.

Three studies compared bilinguals to monolinguals on 15 indicators of executive processing (EP). Most of the indicators compare a neutral or congruent baseline to a condition that should require EP. For each of the measures there was no main effect of group and a highly significant main effect of condition. The critical marker for a bilingual advantage, the Group×Condition interaction, was significant for only one indicator, but in a pattern indicative of a bilingual disadvantage. Tasks include antisaccade (Study 1), Simon (Studies 1-3), flanker (Study 3), and color-shape switching (Studies 1-3). The two groups performed identically on the Raven's Advanced Matrices test (Study 3). Analyses on the combined data selecting subsets that are precisely matched on parent's educational level or that include only highly fluent bilinguals reveal exactly the same pattern of results. A problem reconfirmed by the present study is that effects assumed to be indicators of a specific executive process in one task (e.g., inhibitory control in the flanker task) frequently do not predict individual differences in that same indicator on a related task (e.g., inhibitory control in the Simon task). The absence of consistent cross-task correlations undermines the interpretation that these are valid indicators of domain-general abilities. In a final discussion the underlying rationale for hypothesizing bilingual advantages in executive processing based on the special linguistic demands placed on bilinguals is interrogated.

Predictions about the Cognitive Consequences of Language Switching on Executive Functioning Inspired by the Adaptive Control Hypothesis Fail More Often than Not.

The adaptive control hypothesis developed by Green and Abutalebi is the most influential theory of bilingual language control. The focus of this article is on the predictions that other researchers have derived based on the three different modes of interactional context described by the hypothesis. Foremost, that dual-language contexts should enhance domain-general executive functions more than single-language contexts. Several recent and ambitious behavioral tests of these predictions are reviewed. Although there was some evidence that dual-language contexts are associated with smaller switch costs, the evidence is inconsistent and there were no similar advantages for inhibitory control. The hypothesis also predicts neuroanatomical adaptations to the three types of interactional context. A careful evaluation of the relevant fMRI and ERP studies that take into account whether behavioral differences align with neuroscience differences and resolves valence ambiguities led to the conclusion that the neuroscience evidence for the hypothesis is, at best, inconsistent. The study also includes new analyses of two large-sample studies that enable the identification of relatively pure cases of single-language bilinguals, dual-language bilinguals, and dense-code switchers. Across nine different measures of executive functioning, the predicted advantage of the dual-language context never materialized. The hypotheses derived from the adaptive control hypothesis do not accurately predict behavioral performance on tests of executive functioning and do not advance our understanding as to what dimensions of bilingualism may lead to enhancements in specific components of executive functioning.

Autism Traits Predict Self-reported Executive Functioning Deficits in Everyday Life and an Aversion to Exercise.

Are Autism Quotient (AQ) scores related to executive functioning (EF)? We sampled 200 students of normal intelligence and examined the relationship between AQ scores and: (a) 5 self-ratings of EF, (b) 5 performance-based measures of EF, and (c) 5 types of activities or experiences that are assumed to recruit EF and sometimes enhance EF. Our findings reveal that as AQ scores increase, self-rated EF ability decreases. AQ scores and self-reported EF measures do not correlate with objective EF task performance. Furthermore, AQ scores were shown to be negatively associated with many specific types of physical activity. As AQ scores increase, individuals report fewer positive reasons for exercise and more rationalizations for not engaging in more exercise.

Interference scores have inadequate concurrent and convergent validity: Should we stop using the flanker, Simon, and spatial Stroop tasks?

BACKGROUND: Two-hundred one college undergraduates completed four nonverbal interference tasks (Simon, spatial Stroop, vertical Stroop, and flanker) and trait scales of self-control and impulsivity. Regression analyses tested 11 predictors of the composite interference scores derived from three of the four tasks and each task separately. The purpose of the study was to examine the relationships between laboratory measures of self-control, self-report measures, and the degree to which control might be related to extensive experience in activities that logically require self-control. RESULTS: Fluid intelligence and sex were significant predictors of the composite measure, but bilingualism, music training, video gaming, mindfulness/meditation, self-control, impulsivity, SES, and physical exercise were not. CONCLUSIONS: Common laboratory measures of inhibitory control do not correlate with self-reported measures of self-control or impulsivity and consequently appear to be measuring different constructs. Bilingualism, mindfulness/meditation, playing action video games, and music training or performance provide weak and inconsistent improvements to laboratory measures of interference control. Flanker, Simon, and spatial Stroop effects should not be used or interpreted as measures of domain-general inhibitory control.

The alchemy of confirmation bias transmutes expectations into bilingual advantages: A tale of two new meta-analyses.

Five recent meta-analyses of the bilingual advantage in executive functioning hypothesis have converged on the outcome that the mean effect size is very small and that the incidence of statistically significant bilingual advantages is very low (about 15% of all comparisons). Those analyses that used the PET-PEESE method to correct for publication bias show mean effect sizes that are not different from zero and sometimes negative. In contrast, van den Noort and colleagues provide a sixth review of 46 studies published before October 31, 2018, that appears to produce a very different outcome, namely that more than half the studies yield clear support for the bilingual advantage hypothesis. We show that the deviance is due in part to search terms that yielded far fewer relevant studies, but more importantly to a subjective method of evaluating the results of each study that enables confirmation biases on the part of study authors and meta-analysts to substantially distort the objective pattern of results. A seventh meta-analysis, by Armstrong and colleagues, reports significant bilingual advantages of g = 0.48 for 32 samples using Simon and Stroop colour-word interference tasks that tested older adults. However, all effects were entered into the funnel plots as positive even though many were negative (bilingual disadvantages). This and other striking anomalies are consistent with the view that confirmation bias can suspend critical judgement and promulgate errors. Meta-analyses that use preregistration and a many-labs collaboration can better control for both publication and experimenter biases.

On the ambiguity regarding the relationship between sequential congruency effects, bilingual advantages in cognitive control, and the disengagement of attention.

Grundy, Bialystok, and colleagues have reported that at short response-stimulus intervals bilinguals have smaller sequential congruency effects in flanker tasks compared to monolinguals. They interpret these differences to mean that bilinguals are more efficient at disengaging attentional control. Ten empirical studies are presented that show no differences between bilinguals and monolinguals under conditions that produced robust sequential congruency effects. These null results are discussed with respect to the rate at which sequential congruency effects dissipate and the fact these effects are not adaptive in the sense of improving overall performance. Arguments made by Goldsmith and Morton [1] that smaller sequential congruency effects should not be interpreted as "advantages" are extended. Evidence is also presented that neither simple congruency effects, nor sequential congruency effects, correlate across tasks. This lack of convergent validity is inconsistent with the hypothesis that either provides a measure of domain-general control that could underlie an advantage accrued through experience in switching languages. Results from other tasks purporting to show bilingual advantages in the disengagement of attention are also reviewed. We conclude that sequential congruency effects in nonverbal interference tasks and differences in the rate of disengaging attention are unlikely to contribute to our understanding of bilingual language control and that future research might productively examine differences in proactive rather than reactive control.

Other Language Proficiency Predicts Unique Variance in Verbal Fluency Not Accounted for Directly by Target Language Proficiency: Cross-Language Interference?

The purpose of the study was to investigate cross-language effects in verbal fluency tasks where participants name in English as many exemplars of a target as they can in one minute. A series of multiple regression models were used that employed predictors such as self-rated proficiency in English, self-rated proficiency in a language other than English, a picture naming task used to measure productive vocabulary, the percentage of English use, and the frequency of language switching. The main findings showed that self-rated proficiency in the non-English language accounted for unique variance in verbal fluency that was not accounted for directly by self-rated proficiency in English. This outcome is consistent with cross-language interference, but is also consistent with an account that assumes bilingual disadvantages in verbal fluency and picture naming are due to bilinguals having weaker links between semantic concepts and their phonological form. The present study is also discussed in terms of a broader framework that questions whether domain-general inhibition exists and also whether it plays an important role in bilingual language control.

Bilingual Advantages in Inhibition or Selective Attention: More Challenges.

A large sample (N = 141) of college students participated in both a conjunctive visual search task and an ambiguous figures task that have been used as tests of selective attention. Tests for effects of bilingualism on attentional control were conducted by both partitioning the participants into bilinguals and monolinguals and by treating bilingualism as a continuous variable, but there were no effects of bilingualism in any of the tests. Bayes factor analyses confirmed that the evidence substantially favored the null hypothesis. These new findings mesh with failures to replicate language-group differences in congruency-sequence effects, inhibition-of-return, and working memory capacity. The evidence that bilinguals are better than monolinguals at attentional control is equivocal at best.

The role of test-retest reliability in measuring individual and group differences in executive functioning.

BACKGROUND: Studies testing for individual or group differences in executive functioning can be compromised by unknown test-retest reliability. NEW METHOD: Test-retest reliabilities across an interval of about one week were obtained from performance in the antisaccade, flanker, Simon, and color-shape switching tasks. There is a general trade-off between the greater reliability of single mean RT measures, and the greater process purity of measures based on contrasts between mean RTs in two conditions. The individual differences in RT model recently developed by Miller and Ulrich was used to evaluate the trade-off. RESULTS: Test-retest reliability was statistically significant for 11 of the 12 measures, but was of moderate size, at best, for the difference scores. The test-retest reliabilities for the Simon and flanker interference scores were lower than those for switching costs. COMPARISON WITH EXISTING METHODS: Standard practice evaluates the reliability of executive-functioning measures using split-half methods based on data obtained in a single day. Our test-retest measures of reliability are lower, especially for difference scores. These reliability measures must also take into account possible day effects that classical test theory assumes do not occur. CONCLUSIONS: Measures based on single mean RTs tend to have acceptable levels of reliability and convergent validity, but are "impure" measures of specific executive functions. The individual differences in RT model shows that the impurity problem is worse than typically assumed. However, the "purer" measures based on difference scores have low convergent validity that is partly caused by deficiencies in test-retest reliability.

Bilingual advantages in executive functioning either do not exist or are restricted to very specific and undetermined circumstances.

The hypothesis that managing two languages enhances general executive functioning is examined. More than 80% of the tests for bilingual advantages conducted after 2011 yield null results and those resulting in significant bilingual advantages tend to have small sample sizes. Some published studies reporting significant bilingual advantages arguably produce no group differences if more appropriate tests of the critical interaction or more appropriate baselines are used. Some positive findings are likely to have been caused by failures to match on demographic factors and others have yielded significant differences only with a questionable use of the analysis-of-covariance to "control" for these factors. Although direct replications are under-utilized, when they are, the results of seminal studies cannot be reproduced. Furthermore, most studies testing for bilingual advantages use measures and tasks that do not have demonstrated convergent validity and any significant differences in performance may reflect task-specific mechanism and not domain-free executive functions (EF) abilities. Brain imaging studies have made only a modest contribution to evaluating the bilingual-advantage hypothesis, principally because the neural differences do not align with the behavioral differences and also because the neural measures are often ambiguous with respect to whether greater magnitudes should cause increases or decreases in performance. The cumulative effect of confirmation biases and common research practices has either created a belief in a phenomenon that does not exist or has inflated the frequency and effect size of a genuine phenomenon that is likely to emerge only infrequently and in restricted and undetermined circumstances.

Bilingual advantages in executive functioning: problems in convergent validity, discriminant validity, and the identification of the theoretical constructs.

A sample of 58 bilingual and 62 monolingual university students completed four tasks commonly used to test for bilingual advantages in executive functioning (EF): antisaccade, attentional network test, Simon, and color-shape switching. Across the four tasks, 13 different indices were derived that are assumed to reflect individual differences in inhibitory control, monitoring, or switching. The effects of bilingualism on the 13 measures were explored by directly comparing the means of the two language groups and through regression analyses using a continuous measure of bilingualism and multiple demographic characteristics as predictors. Across the 13 different measures and two types of data analysis there were very few significant results and those that did occur supported a monolingual advantage. An equally important goal was to assess the convergent validity through cross-task correlations of indices assume to measure the same component of executive functioning. Most of the correlations using difference-score measures were non-significant and many near zero. Although modestly higher levels of convergent validity are sometimes reported, a review of the existing literature suggests that bilingual advantages (or disadvantages) may reflect task-specific differences that are unlikely to generalize to important general differences in EF. Finally, as cautioned by Salthouse, assumed measures of executive functioning may also be threatened by a lack of discriminant validity that separates individual or group differences in EF from those in general fluid intelligence or simple processing speed.