The FIDL measures cognitive and behavioural flexibility as it shows up in everyday life, treating flexibility as a trait spread across five dimensions rather than a single laboratory skill.
It was developed by Horne, Chen, and Irish (2024) from a large literature-derived item pool, refined by an international expert consortium and reduced by factor analysis in a United States adult sample spanning the adult lifespan.
The total score is internally consistent, and the scale reproduces expected age-related patterns and correlates in the predicted direction with the Cognitive Flexibility Inventory while remaining distinct from it.
Evidence rests on a single sample of healthy adults: there is no test-retest data, no confirmatory factor analysis, and no clinical norms or cutoffs, so its transdiagnostic use is still a design goal rather than a demonstrated property.
At a Glance
Items
21, across five subscales (Repetition 6, Switching 5, Predictability/Control 4, Routine 3, Thoughts/Beliefs 3)
Administration time
About 20 minutes (Horne et al., 2024)
Response format
5-point scale, 1 = Never to 5 = All the time; each statement rated for the previous two weeks
Subscales or scores
Total score plus five subscales; positively worded items reverse-scored; higher scores indicate greater inflexibility; total range 21-105
Validated ages
Adults 19-78 years (single United States sample)
License
Open access. Published under CC BY 4.0; free to use with attribution (Horne et al., 2024)
Original citation
Horne, Chen, & Irish (2024), British Journal of Clinical Psychology
Introduction
The Flexibility in Daily Life scale (FIDL) is a 21-item self-report questionnaire designed to capture natural expressions of cognitive and behavioural flexibility in everyday life. Developed by Horne, Chen, and Irish (2024), it measures the capacity to switch between task sets or adopt alternative viewpoints, and to engage flexibly in a diverse range of activities and behaviours across daily contexts.
Unlike performance-based neuropsychological tasks that measure cognitive flexibility “in the moment” under structured laboratory conditions (such as the Wisconsin Card Sorting Test), the FIDL assesses trait-level flexibility as it manifests across diverse real-world settings (Horne et al., 2024). This ecological orientation is intended to reflect how flexibility, or its absence, bears on daily functioning.
Understanding Flexibility in Daily Life
The capacity to adjust thinking and behaviour in response to environmental change is an adaptive feature of human cognition that varies between individuals and shifts across the lifespan (Anderson, 2002; Cepeda et al., 2001; Uddin, 2021). Contemporary accounts increasingly treat cognitive and behavioural flexibility as trait-level constructs situated along a continuum, whose extremes represent maladaptive entrenched rigidity at one end and unconstrained hyper-flexibility at the other (Armbruster et al., 2012; Uddin, 2021).
Cognitive and behavioural inflexibility is a recurring feature across neuropsychiatric conditions, and the developers positioned the FIDL as a transdiagnostic measure spanning neurodevelopmental, neurodegenerative, acquired-brain-injury, and psychiatric presentations (Uddin, 2021; Horne et al., 2024). Because performance on laboratory flexibility tasks does not always correspond to flexible or inflexible behaviour in daily life (Geurts et al., 2009), a self-report measure anchored in everyday situations addresses a distinct question from task-based assessment.
Theoretical Foundation
The FIDL was built using a deductive scale-development approach aimed at capturing common themes across the flexibility literature and across neuropsychiatric diagnoses (Horne et al., 2024). The developers argued that existing measures had two main limitations. Performance-based tasks focus on isolated aspects of flexibility under structured conditions and do not capture the full range of flexible thoughts and behaviours displayed across daily contexts. Existing self-report measures are often unidimensional, disorder-specific, or narrow in focus (for example, flexibility only in response to stress), which limits their use as broad transdiagnostic tools.
The scale conceptualises flexibility as comprising several interconnected dimensions: repetitive behaviours, the ability to switch mental or task sets, tolerance for unpredictability, reliance on routines, and rigidity of thoughts and beliefs (Horne et al., 2024). By combining cognitive and behavioural content and spanning multiple everyday situations, the FIDL was intended to provide a multidimensional, ecologically framed assessment suitable across the adult lifespan.
🧠Key insight: The FIDL’s contribution is ecological framing. By asking how flexibility expresses itself in daily life rather than during a structured task, it targets a form of validity that laboratory flexibility measures do not always capture (Geurts et al., 2009; Horne et al., 2024).
Key Features
Assessment Characteristics
21 items providing a multidimensional self-report assessment
About 20 minutes to complete (Horne et al., 2024)
5-point response scale, from “Never” to “All the time”
Five-factor structure measuring distinct dimensions of flexibility
Trait-level self-report anchored in daily-life contexts rather than task performance
Validated in adults 19-78 years in a single United States sample
Open access under CC BY 4.0, free to use with attribution
Dimensions Assessed
The FIDL comprises five validated subscales capturing distinct facets of cognitive and behavioural flexibility (Horne et al., 2024):
Repetition (6 items) – repetitive and stereotyped behaviours in daily life
Switching (5 items) – ability to adapt one’s task or mental set
Predictability/Control (4 items) – preference for structured, predictable environments
Routine (3 items) – reliance on and preference for established routines
Thoughts/Beliefs (3 items) – rigidity of thinking styles and beliefs
Versions and Adaptations
No short forms, translations, or revised versions of the FIDL were identified during verification. The scale exists as the single 21-item form introduced by Horne et al. (2024). The developers note that confirmatory factor analysis in independent samples and validation in clinical populations remain to be conducted.
Research Applications
Lifespan research – tracking natural changes in self-reported flexibility across adulthood
Transdiagnostic assessment – a common metric of flexibility intended for use across diverse conditions (validation in clinical groups still needed)
Multidimensional profiling – characterising which facets of flexibility differ between individuals or groups
Rate how often each statement has applied to you over the previous two weeks, across five dimensions of daily-life flexibility.
Scoring and Interpretation
Response Format
Respondents rate how frequently each statement has applied to them over the previous two weeks using a 5-point scale (Horne et al., 2024):
1 = Never
2 = Rarely
3 = Sometimes
4 = Often
5 = All the time
Illustrative Items
The FIDL is open access under CC BY 4.0. The complete 21-item set, with subscale assignments and scoring key, is published in the Supporting Information of the development article (Horne et al., 2024) and can be reproduced with attribution. Because the authoritative item wording lives in that source, it is not paraphrased here; consult the article directly to build or verify an administration.
Scoring Procedure
Reverse-score the positively worded items so that higher values consistently reflect greater inflexibility.
Subscale scores: sum the items assigned to each of the five subscales (Repetition 6, Switching 5, Predictability/Control 4, Routine 3, Thoughts/Beliefs 3).
The exact item numbering and subscale assignments are given in the development article’s Supporting Information (Horne et al., 2024).
Score Interpretation and Norms
The development study did not publish score norms, clinical cutoffs, or interpretive bands, and none are offered here. Scores are interpreted relative to the sample or comparison group under study. Higher total and subscale scores reflect greater inflexibility; lower scores reflect greater flexibility (Horne et al., 2024).
The one interpretive pattern the study did establish is age-related. Across the adult lifespan the FIDL showed a U-shaped (quadratic) relationship with age for the total score and the Repetition, Routine, and Thoughts/Beliefs subscales, with peak flexibility (lowest inflexibility) in middle adulthood, and a linear decline in flexibility with age for the Switching and Predictability/Control subscales (Horne et al., 2024). These patterns describe the validation sample and are not normative cutoffs.
Recruited from Amazon Mechanical Turk via CloudResearch; United States residents
Stratified across four age bands (18-25, 26-40, 41-59, 60+)
Exclusions: Mini-ACE score below 22, self-reported acquired brain injury or neurological condition, and evidence of automated/bot completion
Item Development and Factor Structure
Items were developed in stages (Horne et al., 2024): an initial pool of 216 items drawn from existing flexibility questionnaires across neuropsychiatric populations was reduced to 30 items capturing common themes; an international expert consortium of neurologists, psychiatrists, and psychologists from 14 countries refined the pool; and a 37-item pilot version was carried forward for validation.
Exploratory factor analysis supported the final structure:
Sampling adequacy: KMO = .89; Bartlett’s test of sphericity χ²(666) = 4526.88, p < .001
Solution: parallel analysis supported a five-factor solution accounting for approximately 49% of variance
Item retention: items with loadings below .40 or cross-loadings of .30 or greater were removed, leaving 21 items across five factors
The five factors were Repetition, Switching, Predictability/Control, Routine, and Thoughts/Beliefs, spanning both cognitive (Switching, Thoughts/Beliefs) and behavioural (Repetition, Routine) content alongside a preference/tolerance dimension (Predictability/Control) (Horne et al., 2024).
Reliability Evidence
Internal consistency (Cronbach’s alpha; Horne et al., 2024):
Total FIDL score: α = .88
Repetition: α = .84
Switching: α = .80
Predictability/Control: α = .78
Routine: α = .70
Thoughts/Beliefs: α = .69
The total score showed good internal consistency; subscale reliabilities ranged from .69 to .84, with the two shortest subscales (Routine and Thoughts/Beliefs, three items each) at or just below the conventional .70 threshold. Split-half reliability for the total score was r = .86. Test-retest reliability was not reported, so the temporal stability of the scale is not yet established (Horne et al., 2024).
Validity Evidence
Convergent and discriminant validity: The FIDL correlated with the Cognitive Flexibility Inventory (CFI; Dennis & Vander Wal, 2010) in the expected direction. Because the two instruments are scored in opposite directions, the FIDL total score showed a moderate negative correlation with the CFI total (r = -.41). The FIDL correlated more strongly with the CFI Control subscale (r = -.47) than with the CFI Alternatives subscale (r = -.15). The moderate rather than very high magnitude supports that the FIDL measures a related but distinct construct: it emphasises broader behavioural flexibility and daily-life manifestations, whereas the CFI focuses on cognitive flexibility in response to stressful situations (Horne et al., 2024).
Age-related (construct) validity: The FIDL reproduced expected lifespan patterns, providing evidence of construct validity. Significant U-shaped (quadratic) associations with age emerged for the total score and the Repetition, Routine, and Thoughts/Beliefs subscales, with peak flexibility in middle adulthood, consistent with prior task-switching work (Cepeda et al., 2001; Kupis et al., 2021). Significant linear associations emerged for the Switching and Predictability/Control subscales, indicating a decline in flexibility with increasing age (Horne et al., 2024). These differential trajectories across subscales support the multidimensional conception of the scale.
Limitations and Future Directions
The developers acknowledged several limitations (Horne et al., 2024):
Single-sample validation: the factor structure was established via exploratory analysis in one sample and awaits confirmatory analysis in an independent sample.
Healthy adults only: validation in clinical populations with known flexibility deficits is still needed.
No test-retest data: temporal stability is not yet established.
Cultural scope: validated only in United States residents.
No clinical anchors: associations with functional outcomes and disorder severity have not yet been examined, and no cutoffs or norms exist.
Usage Guidelines and Applications
Appropriate Uses
Assessing trait-level, self-reported flexibility as it manifests in daily-life contexts
Characterising multidimensional flexibility profiles across the five subscales
Studying age-related variation in flexibility across the adult lifespan
Complementing performance-based flexibility measures with an ecological self-report
Design Considerations
Score direction: the FIDL is scored so that higher values mean greater inflexibility; report the direction explicitly to avoid confusion with flexibility-scored measures such as the CFI.
Subscale length: the Routine and Thoughts/Beliefs subscales have only three items each and lower reliability (α = .70 and .69); interpret short-subscale scores cautiously.
No norms: use within-study comparisons rather than absolute cutoffs, which do not exist.
Self-report scope: the FIDL measures perceived/experienced flexibility, not cognitive performance, and should not stand in for neuropsychological testing.
Cultural Considerations
The scale was validated only in a United States sample recruited online. Its performance in other cultural and linguistic contexts, and in older or younger age groups outside 19-78 years, has not been established (Horne et al., 2024).
No clinical validation yet; transdiagnostic use is a design goal, not an established property
No test-retest evidence and no norms or cutoffs
Not appropriate as a sole diagnostic criterion, as a substitute for performance-based flexibility testing, or for populations outside the validated age range
Copyright and Usage Responsibility: Check that you have the proper rights and permissions to use this assessment tool in your research. This may include purchasing appropriate licenses, obtaining permissions from authors/copyright holders, or ensuring your usage falls within fair use guidelines.
The Flexibility in Daily Life scale is published open access under a Creative Commons Attribution 4.0 (CC BY 4.0) licence as part of the development article. The scale and its item set may be used, reproduced, and adapted with proper attribution to the source. No commercial licence is required.
Proper Attribution: When using or referencing this scale, cite the original development:
Horne, K., Chen, T., & Irish, M. (2024). Development of the Flexibility in Daily Life scale to measure multidimensional cognitive and behavioural flexibility in health and disease. British Journal of Clinical Psychology, 64(2), 315-329. https://doi.org/10.1111/bjc.12505
Horne, K., Chen, T., & Irish, M. (2024). Development of the Flexibility in Daily Life scale to measure multidimensional cognitive and behavioural flexibility in health and disease. British Journal of Clinical Psychology, 64(2), 315-329. https://doi.org/10.1111/bjc.12505
Theoretical Foundation:
Anderson, P. (2002). Assessment and development of executive function (EF) during childhood. Child Neuropsychology, 8(2), 71-82. https://doi.org/10.1076/chin.8.2.71.8724
Armbruster, D. J. N., Ueltzhöffer, K., Basten, U., & Fiebach, C. J. (2012). Prefrontal cortical mechanisms underlying individual differences in cognitive flexibility and stability. Journal of Cognitive Neuroscience, 24(12), 2385-2399. https://doi.org/10.1162/jocn_a_00286
Cepeda, N. J., Kramer, A. F., & Gonzalez de Sather, J. C. M. (2001). Changes in executive control across the life span: Examination of task-switching performance. Developmental Psychology, 37(5), 715-730. https://doi.org/10.1037/0012-1649.37.5.715
Uddin, L. Q. (2021). Cognitive and behavioural flexibility: Neural mechanisms and clinical considerations. Nature Reviews Neuroscience, 22(3), 167-179. https://doi.org/10.1038/s41583-021-00428-w
Convergent Validity:
Dennis, J. P., & Vander Wal, J. S. (2010). The Cognitive Flexibility Inventory: Instrument development and estimates of reliability and validity. Cognitive Therapy and Research, 34(3), 241-253. https://doi.org/10.1007/s10608-009-9276-4
Ecological Validity:
Geurts, H. M., Corbett, B., & Solomon, M. (2009). The paradox of cognitive flexibility in autism. Trends in Cognitive Sciences, 13(2), 74-82. https://doi.org/10.1016/j.tics.2008.11.006
Age-Related Research:
Kupis, L., Goodman, Z. T., Kornfeld, S., Hoang, S., Romero, C., Dirks, B., Dehoney, J., Chang, C., Spreng, R. N., Nomi, J. S., & Uddin, L. Q. (2021). Brain dynamics underlying cognitive flexibility across the lifespan. Cerebral Cortex, 31(11), 5263-5274. https://doi.org/10.1093/cercor/bhab156
Related Assessments: CFI: Cognitive Flexibility Inventory and CFS: Cognitive Flexibility Scale (links added when their pages go live).
Platypuses thriving in water and on land, embodying the adaptability and everyday flexibility the FIDL is designed to measure.
Frequently Asked Questions
What does the FIDL measure?
It measures cognitive and behavioural flexibility as it naturally manifests in daily life, across five dimensions: repetitive behaviours, task or mental set switching, tolerance for unpredictability, reliance on routines, and rigidity of thoughts and beliefs. Unlike laboratory tasks, it assesses trait-level flexibility across everyday situations.
How is the FIDL scored?
After reverse-scoring the positively worded items, sum the items within each of the five subscales and sum all 21 items for a total score (range 21 to 105). Higher scores indicate greater inflexibility or rigidity; lower scores indicate greater flexibility. The subscales contain 6 (Repetition), 5 (Switching), 4 (Predictability/Control), 3 (Routine), and 3 (Thoughts/Beliefs) items.
How reliable is the FIDL?
In the development study the total score had good internal consistency (Cronbach's alpha = .88), with subscale alphas ranging from .69 to .84 and split-half reliability of .86. The two three-item subscales (Routine .70, Thoughts/Beliefs .69) are the least reliable. Test-retest reliability has not yet been reported.
Is the FIDL free to use?
Yes. The scale was published open access under a Creative Commons Attribution 4.0 licence, and the full item set appears in the article's Supporting Information. It can be used and adapted with proper citation of the development article (Horne, Chen, & Irish, 2024). No commercial licence is required.
Does the FIDL have clinical cutoffs or norms?
No. The development study did not publish score norms, clinical cutoffs, or interpretive bands, and validation was conducted only in healthy adults. Scores are best interpreted relative to a comparison group within a study rather than against absolute thresholds.
How does the FIDL differ from the Cognitive Flexibility Inventory (CFI)?
The FIDL assesses multidimensional cognitive and behavioural flexibility across everyday contexts with five subscales, whereas the CFI focuses on cognitive flexibility in response to stressful situations. The two correlate moderately and in the expected direction (the FIDL total showed r = -.41 with the CFI total, negative because the scales are scored in opposite directions), supporting related but distinct constructs.
Across what ages has the FIDL been validated?
It was validated in adults aged 19 to 78 years in a single United States sample. Flexibility followed a U-shaped pattern with age for the total score and several subscales, peaking in middle adulthood, with a linear age-related decline on the Switching and Predictability/Control subscales. It has not been validated outside this age range or in other cultural settings.
