Plate Nº 42 · recorded September 29, 2026
Health & Medicine ResearchReported finding
Night Owls Face Higher Risk of Early Disability Retirement
Finnish researchers tracked 5,679 adults for 12 years and found evening chronotypes were 1.7 times more likely than morning types to receive a disability pension.
By Marcus Bennett4 min read742 words
In brief
- Evening chronotypes were 1.7 times as likely as morning types to receive a disability pension over 12 years of follow-up.
- The study followed 5,679 adults from Finland's 1966 Northern Finland birth cohort, assessed at age 46 and tracked via national registers.
- Chronotype is an innate, genetically influenced trait; the observational design means the study cannot prove cause and effect.
People whose bodies naturally run late — the classic "night owls" — are 1.7 times as likely as morning people to retire early on a disability pension, according to a study published online in the journal Occupational & Environmental Medicine.
The finding comes from a 12-year follow-up of middle-aged adults in Finland, and it held for both men and women even after the researchers accounted for education level and type of occupation.
What is a chronotype?
Chronotype is the body's built-in schedule for sleeping and waking. Scientists sort people into three broad groups based on when their body functions and alertness peak: morning types (M-types), intermediate types, and evening types (E-types).
Earlier research had already suggested that evening types tend to have poorer health and more trouble at work than morning types. But the connection between chronotype and disability pensions — a specific marker of severe, long-term health decline — had not been firmly established. The new study was designed to strengthen that evidence.
How the study worked
The researchers drew on an ongoing population study that began in 1966 and eventually included 96% of everyone born in two northern provinces of Finland.
In 2012, when participants were 46 years old, they answered questions designed to pinpoint their chronotype. The questions covered how easily they woke in the morning, how tired they felt during the first half-hour after waking, when they preferred to work, and whether they considered themselves morning or evening people.
The baseline sample included 5,679 people: 2,597 men and 3,082 women. Of these, 253 men (9.7%) and 381 women (12.4%) were classified as evening types, while 1,182 men (46%) and 1,355 women (44%) qualified as morning types. Everyone else fell into the intermediate category.
The researchers then linked these classifications to Finland's national registers, which track work and pension records.
The results
Over the 12-year follow-up, 135 men (5.2%) and 249 women (8.1%) were granted their first disability pension.
Being an evening type at age 46 was associated with a 1.7-fold greater likelihood of receiving a disability pension over the following 12 years, compared with being a morning type. The pattern was the same for men and women, and it persisted after adjusting for socioeconomic factors such as education and occupation.
In Finland, a disability pension is granted only after a period of severe, long-term health decline. That makes the elevated pension rate among evening types a meaningful signal of worsening health, not a bureaucratic technicality.
Why might night owls be at higher risk?
The researchers point to two likely drivers. First, evening types may make less healthy lifestyle choices. Second, their internal body clocks are frequently disrupted, which can produce sleep problems.
Chronotype itself is not a choice. It is an innate biological trait with a strong genetic basis — a point the study supported by analyzing participants' genetic information. Previous research has shown that chronotype remains very stable throughout adulthood.
Important caveats
The study has real strengths. It followed a large group of people drawn from all sectors of the economy and a wide range of occupations over more than a decade.
But it is an observational study, so it cannot prove cause and effect. Evening chronotype and disability pension may be linked through pathways the study did not fully capture. The researchers also note that changes in health and life circumstances in the years after the 2012 baseline survey may not have been accounted for.
Why it matters
Even with those limits, the researchers argue the pattern is concerning as evening types approach their 50s and 60s. For some, health may have deteriorated enough to erode their capacity to work, making disability pensions more likely than for morning types.
"People who are E-type represent a significant proportion of the population and their health and ability to continue working until retirement age pose challenges for sustainable economies," the researchers say.
In other words, if a substantial share of the workforce is biologically wired for late hours but lives in a society built around early mornings, the cost may eventually show up in public pension budgets — not just in individual fatigue.
The study appears as: Evening chronotype and disability pensions: 12-year register-based follow up of middle-aged adults from the Northern Finland birth cohort 1966, Occupational and Environmental Medicine (2026). DOI: 10.1136/oemed-2026-110995.
via Medical Xpress (Source)
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