Detaching From the Nine-to-Five: How Retirement and Genetics Are Related to Chronotype

Area of Science:

• Chronobiology
• Behavioral Genetics
• Sleep Science

Background:

• Sleep-wake rhythms are governed by the interplay between the biological clock and the 'social clock' (work-life balance).
• Retirement may reduce social constraints, potentially allowing genetic factors to more strongly influence sleep patterns.

Purpose of the Study:

• To investigate changes in wake-up times and chronotypes between employment and retirement.
• To determine the influence of social factors versus genetic predispositions on chronotype.

Main Methods:

• Analysis of data from 20,189 participants in the Netherlands Twin Register.
• Utilized mixed-effects models, regression, and quantile regression to analyze wake-up times and chronotypes.
• Employed polygenic scores for morningness to assess genetic influence on chronotype.

Main Results:

• Later wake-up times were observed on non-working days compared to working days for both early and late risers.
• Employment status predicted wake-up time on working days, but not chronotype.
• Genetic predisposition for morningness influenced chronotype regardless of employment status.

Conclusions:

• The social clock impacts daily wake-up times but does not alter an individual's fundamental chronotype.
• Chronotype is a stable trait, and social influences do not override genetic predispositions.
• This research clarifies the distinct roles of societal and genetic factors in shaping sleep-wake rhythms.