Morningness-Eveningness Questionnaire

Abstract

The Morningness-Eveningness Questionnaire (MEQ), developed by James A. Horne and Olov Östberg in 1976, represents the gold standard psychometric instrument for assessing individual differences in diurnal preference, commonly conceptualized as an individual’s chronotype. Diurnal preference reflects endogenous temporal organization along a continuum ranging from extreme morningness (“larks”) to extreme eveningness (“owls”). Comprising 19 self-report items evaluated on heterogeneous Likert-type scales and discrete time-interval selections, the MEQ generates a composite score ranging from 16 to 86. These numerical scores classify individuals into five distinct chronobiological categories: Definitely Morning Type (70–86), Moderately Morning Type (59–69), Neither / Intermediate Type (42–58), Moderately Evening Type (31–41), and Definitely Evening Type (16–30).

Extensive psychometric investigations over nearly five decades have corroborated the instrument’s robust reliability and concurrent biological validity. Internal consistency estimates across diverse international cohorts consistently demonstrate Cronbach’s alpha values ranging between .78 and .86, coupled with exceptional test-retest stability coefficients exceeding r = .88 across multi-week and multi-month intervals. Crucially, the MEQ displays high convergence with objective physiological markers of the human circadian pacemaker, including the timing of the dim light melatonin onset (DLMO), core body temperature acrophase and bathyphase ($T_{\text{\min}}$), cortisol awakening response (CAR), and actigraphically monitored sleep-wake architecture. While modern structural evaluations reveal multidimensional latent structures—predominantly capturing morning alertness, circadian peak performance, and preferred phase timing—the composite score remains an indispensable metric across clinical chronotherapy, occupational ergonomics, psychiatric research, and experimental chronobiology.

Keywords

Morningness-Eveningness Questionnaire, MEQ, chronotype, circadian rhythm, diurnal preference, sleep-wake cycle, dim light melatonin onset, core body temperature, Horne and Östberg, phase delay, sleep architecture, psychometrics

Authors

The original Morningness-Eveningness Questionnaire was designed and validated by:

• James A. Horne, Ph.D., D.Sc. — Department of Human Sciences, Loughborough University, Leicestershire, United Kingdom. Dr. Horne is a distinguished sleep researcher and neuroscientist renowned for his seminal contributions to sleep function, human circadian biology, and cognitive performance under sleep deprivation.
• Olov Östberg, Ph.D. — Department of Occupational Health, National Board of Occupational Safety and Health, Stockholm, Sweden; later affiliated with the Division of Human Work Sciences, Luleå University of Technology, Luleå, Sweden. Dr. Östberg is an occupational ergonomics expert specializing in circadian adaptation, shift work physiology, and industrial ergonomics.

Subsequent psychometric refinements, including the standardization of continuous visual analogue scales into discrete categorical time blocks adapted for spoken American English and computerized algorithmic scoring (AutoMEQ), were spearheaded by:

• Michael Terman, Ph.D., Jiuan Su Terman, Ph.D., J. B. Rifkin, J. Jacobs, and T. M. White — Center for Light Treatment and Biological Rhythms, New York State Psychiatric Institute, and the Department of Psychiatry, Columbia University College of Physicians and Surgeons, New York, NY, USA.

Purpose

The primary clinical and scientific purpose of the MEQ is to quantitatively measure an individual’s subjective diurnal preference and preferred circadian phase position. Human beings demonstrate marked inter-individual variability in the timing of their physiological, metabolic, and cognitive peaks relative to the 24-hour astronomical day. The MEQ was engineered to capture these systematic variations in a standardized, rapid, and non-invasive manner, bridging the divide between laboratory-based chronobiological assessments and large-scale behavioral screening.

In clinical sleep medicine, the MEQ serves as a foundational diagnostic and treatment-planning instrument. It is routinely deployed to screen for and evaluate circadian rhythm sleep-wake disorders (CRSWD), most notably Delayed Sleep-Wake Phase Disorder (DSWPD) and Advanced Sleep-Wake Phase Disorder (ASWPD). Individuals suffering from DSWPD characteristically obtain MEQ scores localized in the extreme eveningness tier (16–30), manifesting pathological delays in sleep initiation and morning awakening relative to societal demands. Conversely, elderly patients frequently present with ASWPD, mapping onto the extreme morningness tier (70–86).

Furthermore, the MEQ plays a pivotal role in precision psychiatry and chronotherapy. In the management of Seasonal Affective Disorder (SAD) and non-seasonal Major Depressive Disorder (MDD), bright light therapy (phototherapy) yields optimal clinical efficacy when its circadian administration is synchronized to the patient’s individual internal clock rather than arbitrary civil wall-clock time. Using algorithms calibrated against the MEQ (such as the Terman protocol utilized by the Center for Environmental Therapeutics), clinicians calculate the precise morning hour to administer light exposure—typically tailored to occur approximately 8.5 hours after the patient’s calculated melatonin onset or 2 to 2.5 hours prior to spontaneous awakening—thereby maximizing therapeutic antidepressant phase-advances while preventing deleterious phase-delays or hypomanic switches.

In occupational health and ergonomic settings, the questionnaire facilitates the mitigation of social jetlag—the chronic temporal misalignment between biological time and social or professional schedules. Industrial organizations use the MEQ to optimize shift-work scheduling, mitigate fatigue-related operational accidents, and assign high-vigilance operational responsibilities to personnel during their biological peak performance windows.

Psychological Construct

The primary construct assessed by the MEQ is diurnal preference, commonly known as chronotype. Chronotype represents a multidimensional psychobiological trait reflecting individual preferences regarding the timing of sleep, waking, cognitive engagement, and physical activity across the 24-hour cycle. Rather than measuring actual sleep hygiene or sleep duration, the MEQ captures the endogenous temporal orientation of the individual. This construct manifests across several interrelated behavioral and perceptual facets:

1. Preferred Phase Timing (Sleep-Wake Scheduling)

This facet assesses the timing an individual would choose for retiring to bed and waking up if they were completely unrestricted by occupational, family, or social obligations (Items 1 and 2). Morning-oriented individuals spontaneously select early wake times (e.g., 05:00–06:30 h) and early bedtimes (e.g., 20:00–21:00 h). Evening-oriented individuals shift these intervals substantively later (e.g., waking after 11:00 h and sleeping past 02:00 h), reflecting an underlying delay in sleep architecture initiation.

2. Post-Awakening Inertia and Readiness

This dimension quantifies the subjective experience during the transition from sleep to full waking consciousness, known physiologically as sleep inertia (Items 3, 4, 5, 6, and 7). It evaluates dependence on artificial auditory cues (alarm clocks), ease of arising, psychological alertness, subjective vigor, and early-morning appetite. Morning types rapidly dissipate sleep inertia, exhibiting high subjective alertness and early appetite within the first 30 minutes post-awakening, whereas evening types suffer protracted sleep inertia and prolonged hypophagia during the early morning hours.

3. Peak Efficiency and Cognitive-Physical Performance

This dimension operationalizes the subjective “circadian peak”—the daily time window during which cognitive executive functions, sustained attention, and physical endurance reach maximum capacity (Items 9, 11, 15, 16, 17, and 18). Morning types prefer scheduling taxing intellectual tasks (such as two-hour examinations) and demanding physical exertion in the morning hours (08:00–10:00 h). Evening types report profound impairment if forced to perform strenuous physical or intellectual labor at 07:00 h, expressing an overwhelming preference for late-afternoon or nighttime engagement (19:00–23:00 h).

4. Circadian Phase Stability and Flexibility

This component reflects the resilience or rigidity of an individual’s circadian entrainment when challenged by phase shifts, social disruptions, or sleep deprivation (Items 8, 12, 13, and 14). Morning types display strong circadian rigidity: even when retiring several hours later than usual, their endogenous pacemaker triggers awakening at their typical hour without the ability to return to restorative sleep. Evening types show greater phase elasticity, readily extending sleep duration deep into the following day.

5. Subjective Self-Identification

Item 19 encapsulates the conscious meta-cognitive awareness of one’s own chronobiological phenotype (“One hears about ‘morning types’ and ‘evening types.’ Which one of these types do you consider yourself to be?”). Self-concept strongly correlates with empirical behavioral choices, demonstrating that individuals possess pronounced subjective insights into their internal circadian rhythms.

Theoretical Framework

The MEQ is grounded in the foundational principles of mammalian chronobiology, circadian rhythmicity, and the neurobiology of the sleep-wake cycle. The theoretical underpinning of morningness-eveningness rests predominantly on the Two-Process Model of Sleep Regulation initially conceptualized by Alexander Borbély (1982) and expanded by Serge Daan and colleagues.

The Two-Process Model posits that sleep and alertness are governed by the dynamic non-linear interaction of two distinct regulatory forces:

• Process S (The Homeostatic Sleep Drive): An hourglass-like neurochemical pressure that accumulates progressively during sustained wakefulness (primarily mediated by extracellular adenosine accumulation in the basal forebrain and cortex) and dissipates exponentially during slow-wave non-rapid eye movement (NREM) sleep.
• Process C (The Circadian Pacemaker): An endogenous, self-sustaining oscillatory process driven by the master circadian pacemaker localized in the bilateral suprachiasmatic nucleus (SCN) of the anterior hypothalamus. Process C dictates cyclical variations in physiological arousal, body temperature, autonomic tone, and endocrine secretion, operating largely independent of prior sleep duration.

From a theoretical chronobiological perspective, the morningness-eveningness continuum captured by the MEQ reflects structural differences in both Process C and Process S. Chronobiological investigations demonstrate that the endogenous period length (designated by the Greek letter $tau$, or tau) of the human circadian pacemaker varies systematically across individuals. While the average human tau is approximately 24.15 hours, morning-type individuals typically possess an endogenous tau significantly closer to or shorter than 24.0 hours. To entrain to the 24-hour solar day, a short-tau pacemaker requires daily phase-delays, positioning the subjective day earlier in absolute astronomical time.

Conversely, evening-type individuals frequently exhibit a lengthened endogenous tau exceeding 24.2 to 24.4 hours. To synchronize with the 24-hour day, their pacemakers must undergo continuous daily phase-advances via morning zeitgebers (primarily photic inputs transmitted via intrinsically photosensitive retinal ganglion cells along the retinohypothalamic tract). When entrainment forces are insufficient or social environments permit, the evening clock drifts toward a delayed phase angle of entrainment ($psi$).

At the molecular level, these differences are orchestrated by transcriptional-translational feedback loops (TTFLs) involving the core circadian genes: CLOCK, BMAL1 (ARNTL), PERIOD (PER1, PER2, PER3), and CRYPTOCHROME (CRY1, CRY2). Specific single nucleotide polymorphisms (SNPs), such as the variable number tandem repeat (VNTR) polymorphism in PER3 and clock gene variants like CLOCK 3111T/C, have been empirically linked to MEQ scores. Long-repeat PER3 alleles correlate with morningness and elevated homeostatic sleep pressure accumulation, whereas shorter variants associate with eveningness.

Validity

The psychometric validity of the MEQ has been extensively investigated through construct, convergent, criterion, and discriminant validation paradigms.

Biological and Criterion Validity

The paramount strength of the MEQ lies in its profound convergent validity with objective physiological and endocrine biomarkers of the human circadian pacemaker:

• Dim Light Melatonin Onset (DLMO): Regarded as the most reliable biological marker of the human circadian phase, DLMO marks the evening onset of pineal melatonin secretion under dim ambient illumination. Studies demonstrate a robust negative correlation (ranging from r = -.60 to r = -.75) between MEQ scores and the clock time of DLMO. High MEQ scores (morningness) correlate with significantly earlier DLMO timing (often occurring between 19:30 and 21:00 h), whereas low scores (eveningness) correspond to substantially delayed melatonin surges (often between 23:30 and 02:00 h).
• Core Body Temperature Rhythm: The circadian nadir of core body temperature ($T_{\text{\min}}$)—occurring approximately 2 to 3 hours prior to habitual wake time—manifests 1.5 to 2.5 hours earlier in definite morning types than in definite evening types when monitored under continuous constant routine protocols. Horne and Östberg (1976) originally validated the MEQ against oral temperature profiles, demonstrating that morning types achieved peak daytime temperature significantly earlier than evening types.
• Cortisol Awakening Response (CAR): Morning types exhibit an elevated and accelerated CAR, characterized by a sharp rise in salivary free cortisol concentrations within the initial 15 to 45 minutes following morning awakening, whereas evening types demonstrate a flatter, attenuated morning endocrine activation.

Construct and Convergent Behavioral Validity

When evaluated against objective longitudinal behavioral tracking via wrist actigraphy and validated sleep logs, MEQ scores correlate strongly with real-world sleep timing parameters. Midsleep on work-free days (corrected for sleep debt, $MSF_{sc}$) derived from the Munich ChronoType Questionnaire (MCTQ; Roenneberg et al., 2003) correlates with the MEQ at coefficients between r = -.65 and r = -.78. Morning types consistently display earlier sleep onset, earlier wake times, and higher regularity across workdays and free days.

Discriminant Validity

The MEQ shows distinct psychometric divergence from general measures of psychopathology, neuroticism, and baseline insomnia. Although eveningness is epidemiologically associated with elevated risks for mood disorders, substance abuse, and metabolic dysregulation, multivariate regressions confirm that the MEQ measures circadian timing rather than affective distress. Scores do not overlap substantially with subjective sleep quality metrics such as the Pittsburgh Sleep Quality Index (PSQI) when circadian phase is aligned with environmental schedules.

Reliability

The Morningness-Eveningness Questionnaire exhibits exceptional psychometric reliability across diverse demographic strata, geographic zones, and clinical cohorts.

Internal Consistency

Across validation studies spanning North America, Europe, Asia, and Latin America, the MEQ displays high to excellent internal consistency:

• The original validation by Horne and Östberg (1976) reported strong inter-item reliability among English-speaking adults.
• A large-scale evaluation by Chelminski et al. (2000) using a sample of 1,223 American university students demonstrated a Cronbach’s alpha of $\alpha = .82$.
• Cross-cultural translations, including Spanish (Adan & Almirall, 1991), French (Taillard et al., 2004), German (Griefahn et al., 2001), Turkish (Punduk et al., 2005), and Japanese (Ishihara et al., 1984) adaptations, consistently demonstrate Cronbach’s alpha coefficients bounded between .78 and .86, reflecting satisfactory homogeneity among the 19 items without redundant multi-collinearity.

Test-Retest Stability

Because chronotype functions as a stable biological trait during adulthood, the MEQ possesses high test-retest reliability:

• Short-term test-retest assessments across intervals of 1 to 4 weeks have yielded stability coefficients ranging from r = .88 to r = .95.
• Longitudinal evaluations across several months to multi-year windows report coefficients exceeding r = .80, confirming trait stability across mature adult cohorts, barring developmental age shifts (such as the physiological phase-delay observed during adolescence and the progressive phase-advance associated with healthy aging).

Factor Analysis

Although the MEQ was conceptually designed as a unidimensional composite metric, nearly four decades of exploratory factor analyses (EFA) and confirmatory factor analyses (CFA) reveal that the 19 items map onto a multidimensional latent space consisting of 3 to 5 distinct underlying factors.

Representative Multi-Factor Models

Extensive factor-analytic investigations by Smith, Reilly, and Midkiff (1989), Adan and Almirall (1991), and Chelminski et al. (2000) have characterized the following latent dimensions:

• Factor 1: Morning Alertness / Dissipation of Sleep Inertia. Typically encompasses Items 4, 5, 6, 7, and 12. This factor loads heavily on questions evaluating subjective vigilance, hunger, and freshness during the first 30 minutes following morning waking. Factor loadings for Items 5 and 7 routinely exceed .65.
• Factor 2: Peak Efficiency / Daytime Activity Planning. Dominantly encompasses Items 9, 11, 15, 16, and 18. This dimension encapsulates optimal scheduling for demanding mental tests and physical exercise. Items 11 and 15 display strong convergent loadings (often > .60) on this factor.
• Factor 3: Sleep-Wake Timing / Phase Choice. Comprises Items 1, 2, 10, and 17. These items isolate preferred hours for awakening, retiring to bed, and commencing a hypothetical five-hour work shift under unconstrained conditions.
• Factor 4: Morning Anticipation / Rigidity. Captures Items 3, 8, 13, and 14, representing dependence on alarm devices, bedtimes prior to commitment-free days, and sleep-schedule adaptation during shift-work or late-night activities.

Confirmatory Factor Analysis and Model Fit

Confirmatory factor analytic investigations comparing the original unidimensional model against 3-factor, 4-factor, and 5-factor structural configurations consistently demonstrate superior fit for multidimensional models. Goodness-of-fit indices for the commonly accepted 4-factor and 5-factor solutions routinely achieve satisfactory benchmarks:

• Root Mean Square Error of Approximation (RMSEA) $le .055$
• Comparative Fit Index (CFI) $ge .93$
• Tucker-Lewis Index (TLI) $ge .91$
• Standardized Root Mean Square Residual (SRMR) $le .050$

Despite this structural multidimensionality, the 19 items retain substantial common variance. A higher-order, hierarchical general factor of “Diurnal Preference” accounts for approximately 50–60% of the total variance, confirming that summarizing the 19 items into a single composite score remains psychometrically sound for clinical, diagnostic, and epidemiological investigations.

Instrument / Measurement Tool

• Construct Measured: Diurnal preference / Circadian chronotype (Morningness vs. Eveningness).
• Target Population: Adolescents and adults (ages 14 to 85+).
• Administration Modality: Paper-and-pencil self-report or computerized assessment (e.g., AutoMEQ).
• Item Count: 19 items.
• Item Formats: Categorical multiple-choice time bands (e.g., preferred bed/wake hours), 4-point Likert scales, and situational forced-choice behavioral scenarios.
• Scoring Range: 16 to 86 total points. Higher total scores reflect greater morningness; lower total scores reflect greater eveningness.
• Scoring Weight per Item:
  • Items 1, 2, 10, 17, and 18: Scored on a 1 to 5 scale.
  • Items 3, 4, 5, 6, 7, 8, 9, 13, 14, 15, and 16: Scored on a 1 to 4 scale.
  • Items 11 and 19: Scored with weighted values [0, 2, 4, 6] or [1, 2, 4, 6].
  • Item 12: Scored with weighted values [0, 2, 3, 5].
• Diagnostic Classification Thresholds:
  • 70–86: Definitely Morning Type (Extreme Lark)
  • 59–69: Moderately Morning Type (Moderate Lark)
  • 42–58: Neither / Intermediate Type
  • 31–41: Moderately Evening Type (Moderate Owl)
  • 16–30: Definitely Evening Type (Extreme Owl)

Permissions & Fee and Test Year

The original Morningness-Eveningness Questionnaire was developed and published in 1976 by James A. Horne and Olov Östberg in the International Journal of Chronobiology. In 2001 and 2008, standardized American-English adaptations featuring discrete interval choices in place of continuous visual analogue scales were prepared by Michael Terman, Jiuan Su Terman, and colleagues at Columbia University and the New York State Psychiatric Institute under NIH Grant MH42931.

Licensing and Terms of Use: The standardized English instrument is copyrighted by the Center for Environmental Therapeutics (CET). Permission is granted by CET for non-commercial academic research, individual personal use, and clinical psychiatric or medical practice without fee. Commercial distribution, proprietary software integration, or commercial exploitation is strictly prohibited without explicit written authorization from the Center for Environmental Therapeutics. Automated computerized administration and algorithmic scoring are accessible via CET’s online AutoMEQ platform.

References

• Adan, A., & Almirall, H. (1991). Horne & Östberg morningness-eveningness questionnaire: A reduced scale. Personality and Individual Differences, 12(3), 241–253. https://doi.org/10.1016/0191-8869(91)90110-W
• Borbély, A. A. (1982). A two process model of sleep regulation. Human Neurobiology, 1(3), 195–204. https://pubmed.ncbi.nlm.nih.gov/7185792/
• Chelminski, I., Petros, T. V., Plaud, J. J., & Ferraro, F. R. (2000). Psychometric properties of the Reduced Morningness-Eveningness Questionnaire and the Composite Scale of Morningness in a college student population. Journal of Clinical Psychology, 56(11), 1435–1443. https://doi.org/10.1046/j.1439-054x.2001.01149.x
• Horne, J. A., & Östberg, O. (1976). A self-assessment questionnaire to determine morningness-eveningness in human circadian rhythms. International Journal of Chronobiology, 4(2), 97–110. https://pubmed.ncbi.nlm.nih.gov/1027738/
• Ishihara, K., Saitoh, T., Inoue, Y., & Miyata, Y. (1984). Investigation of the morningness-eveningness questionnaire: Its validity and the relationship with activity and personality. The Japanese Journal of Psychology, 55(4), 229–232. https://doi.org/10.4992/jjpsy.55.229
• Punduk, Z., Gür, H., & Ercan, I. (2005). Sabahçıl-akşamcıl anketi Türkçe uyarlamasında güvenilirlik çalışması [A reliability study of the Turkish adaptation of the Morningness-Eveningness Questionnaire]. Türk Psikiyatri Dergisi, 16(1), 40–45. https://pubmed.ncbi.nlm.nih.gov/15793697/
• Roenneberg, T., Wirz-Justice, A., & Merrow, M. (2003). Life between clocks: Daily temporal patterns of human chronotypes. Journal of Biological Rhythms, 18(1), 80–90. https://doi.org/10.1177/0748730402239679
• Smith, C. S., Reilly, C., & Midkiff, K. (1989). Evaluation of three circadian rhythm questionnaires with suggestions for an improved measure of morningness. Journal of Applied Psychology, 74(5), 728–738. https://doi.org/10.1037/0021-9010.74.5.728
• Taillard, J., Philip, P., Chastang, J. F., & Bioulac, B. (2004). Validation of Horne and Östberg Morningness-Eveningness Questionnaire in a middle-aged population of French workers. Journal of Biological Rhythms, 19(1), 76–86. https://doi.org/10.1177/0748730403259849
• Terman, M., Rifkin, J. B., Jacobs, J., & White, T. M. (2001). Morningness-Eveningness Questionnaire (MEQ). New York State Psychiatric Institute, Columbia University. Adapted for the Center for Environmental Therapeutics. https://www.cet.org
• Terman, M., & Terman, J. S. (2005). Light therapy for seasonal and nonseasonal depression: Efficacy, protocol, safety, and side effects. CNS Spectrums, 10(8), 647–663. https://doi.org/10.1017/s1092852900019611

13. Items of the Scale (Questionnaire)