Annals of human biologySep 25, 2013

Comparing two questionnaires to find how sleep timing types vary with latitude

Circadian Biology Weekly Brief ↗PubMed ↗DOI ↗

Updated Mar 31, 2026

Abstract

Chronotype distributions differ between two Brazilian cities, with São Paulo showing a clear shift towards eveningness compared to Natal.

Chronotype refers to the preference for performing activities during specific times of the day.
Two questionnaires, Horne and Östberg (HO) and Munich Chronotype Questionnaire (MCTQ), were used to assess chronotypes among undergraduate students.
MCTQ scores indicated a significant eveningness shift in São Paulo compared to Natal.
HO scores from both cities showed overlapping distributions.
Findings support the idea that geographical location, particularly distance from the equator, may influence sleep phase timing.

Simplified

BACKGROUND: Chronotype, phase preference to perform activities during a 24-hour day, represents distinct circadian temporal organization of living organisms. Morning and evening types can be identified by questionnaires such as Horne and Östberg (HO) and Munich Chronotype Questionnaire (MCTQ). Environmental factors, such as different light-dark cycles experienced at different latitudes, interact with the organisms' circadian timekeeping system. Therefore, chronotype is expected to vary as a result of different geographical locations.

AIM: To identify differences in chronotype distribution in populations of two Brazilian cities, Natal and Sao Paulo, located at different latitudes.

SUBJECTS AND METHODS: Two specific questionnaires, the Horne and Östberg Questionnaire (HO) and the Munich Chronotype Questionnaire (MCTQ), were used to identify chronotypes of undergraduate students from São Paulo and Natal.

RESULTS: The comparison of the curve distributions of HO and MCTQ scores between both cities allowed one to observe that, while HO curves of São Paulo and Natal overlapped, MCTQ curves showed a clear shift towards eveningness in São Paulo.

CONCLUSION: This experiment confirmed results from previous studies that the farther away from the equator, the longer the delay of the sleep phase. It was also concluded that MCTQ is better at detecting this phenomenon.

Full Text

Full text is available at the source.

View Full Text ↗

Comparing two questionnaires to find how sleep timing types vary with latitude

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

What Lands in Your Inbox Each Week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

What Lands in Your Inbox Each Week:

Recent issues from the circadian biology brief