Latitude affects Morningness-Eveningness: evidence for the environment hypothesis based on a systematic review

  title={Latitude affects Morningness-Eveningness: evidence for the environment hypothesis based on a systematic review},
  author={Christoph Randler and Arash Rahafar},
  journal={Scientific Reports},
Morningness-eveningness (M/E) is an individual trait related to a person’s sleep-wake cycle and preference for morning or evening hours. The “environment hypothesis” suggests that M/E is dependent on environmental factors, such as latitude, mean average temperature and photoperiod. We here analyzed a large number of datasets to assess this effect based on a systematic review. Data were from a total of 87 datasets and 35,589 individuals based on 28 countries. Partial correlations correcting for… 

Development of morning-eveningness in adolescence: implications for brain development and psychopathology.

Developmental changes in morning-evening preference may predict both neurodevelopmental and psychological outcomes in adolescents, as well as psychopathology and white matter development, across adolescence.

Self-reported discomfort associated with Daylight Saving Time in Brazilian tropical and subtropical zones

DST at low latitude locations may be disruptive for circadian rhythms, since seasonality of sunrise near the equator is negligible or very mild.

The Relationship Between Morningness–Eveningness, Psychosocial Variables, and Cortisol Reactivity to Stress From a Life History Perspective

Consistent with the hypothesis that some of the psychological, behavioral, and physiological characteristics of morning- and evening-types may represent adaptations to slow and fast life histories,

An hour in the morning is worth two in the evening: association of morning component of morningness–eveningness with single nucleotide polymorphisms in circadian clock genes

Seven single nucleotide polymorphisms in five circadian clock genes were studied and an association of this scale with rs1159814 in RORα was found and confirmed and suggested possibility to take into account the pattern of geographic variation in allele frequency for prioritization of circadian clock polymorphism in candidate gene studies.

Chronotype correlates with developmental index, intelligence and academic achievement: A study based on nationwide indicators

  • C. Randler
  • Psychology
    Chronobiology international
  • 2017
The relationship between M/E and nationwide available data, such as economic variables, school achievement, intelligence and conscientiousness, which is a personality trait, was analysed, finding that conscientiousness was related to morningness, although the results failed the significance level marginally.

Chronotypes and circadian rhythms in university students

ABSTRACT Inter-individual differences have been described in circadian timing organization, including the characteristics of phase preferences known as chronotypes. Social, biological and geophysical

Personality Traits Relate to Chronotype at Both the Phenotypic and Genetic Level.

Phenotypic measures of chronotype and personality showed significant associations at all three of levels of the personality hierarchy, indicating that the relationship between personality and morningness-eveningness is partly due to genetic factors.

Latitudinal trends in human primary activities: characterizing the winter day as a synchronizer

This work analyzes time use surveys from 19 countries accounting for 45% of world population in the middle latitude, revealing winter sunrise synchronizes labor start time below 54 degree, occurring within winter civil twilight.



Morningness–eveningness and the environment hypothesis – A cross-cultural comparison of Turkish and German adolescents

It is shown that the Morning Affect Factor and Morningness scores are equivalent in both countries and this fits into the environment hypothesis suggesting that populations near the equator should be more morning oriented.

Heritability of Morningness‐Eveningness and Self‐Report Sleep Measures in a Family‐Based Sample of 521 Hutterites

It is found that significant heritable influences on human circadian phase and subjective sleep indices can be detected through family‐based studies.


The aim of this study was to analyze gender difference in morningness–eveningness preference using the Horne and Östberg questionnaire in the largest university student population selected so far.

Morningness‐Eveningness Comparison in Adolescents from Different Countries around the World

  • C. Randler
  • Psychology
    Chronobiology international
  • 2008
It was found that climate, longitude, and latitude contribute to chronotype, and adolescents were found to be more morning oriented both toward the East and North.

Differences in sun time within the same time zone affect sleep–wake and social rhythms, but not morningness preference: Findings from a Polish–German comparison study

Morningness–eveningness describes individual preferences for activity at specified times of the day. The present research aimed to test whether sun time entrains humans and whether this effect is

Composite scales of morningness and preferences: Preliminary validity data in Peruvian undergraduates

Preliminary results about the validity of the composite morningness scale (CS) and the early/late preferences scale (PS) in a Peruvian sample partially confirm Bohle et al.'s (2001) hypothesis about preferred rising and retiring times and their relationship with the PS, and actual rising time and its relationships with the CS and PS.