Studies have shown that some of us are naturally much better at braving the morning than others. These "morning larks" have a certain set of brain differences that make them fresh and happy when they wake for the day, whilst "night owls" (these are the genuine scientific terms) are more likely to party late into the night and hate the morning. Of course, you can train yourself to be a morning person with enough perseverance and coffee, but certain sets of genes – called chronotypes – certainly help. 

However, new research has discovered that chronotypes could be drastically more important in your life than previously thought. They found that chronotypes appear to be directly linked to how much sleep you may get and how you perform at work, with larks regularly outperforming their late-night counterparts. 

The research was published in the journal Occupational and Environmental Medicine. 

To find out how chronotypes affect people’s lives, researchers from Finland delved into a large cohort of people currently taking part in the Northern Finland Birth Cohort 1966 Study. This is a study still ongoing that follows the lives of people born in 1966, consisting of over 12,000 participants with an almost 50/50 split between men and women. 

Once aged 46, each participant was asked about various aspects of their life, including sleep patterns, overall health, and work habits. From this data, each person could be grouped into a morning person, called M-type; an evening person, called E-type; or an intermediate chronotype.  

Most men were either M-type (46%) or intermediate (44%), with just 10% being E-type. Women were very similar, with 44% being M-type, 44% intermediate, and 12% E-type. The skew may be due to the age of the population, with older people often waking earlier than adolescents and young adults. 

When compared to the M-types, the E-types were worse off in many different aspects of life, getting less sleep and being more likely to be unmarried and unemployed, even after accounting for other variables. Evening chronotypes have been previously linked to poor health and ability to work, and this study cements a serious divide between the chronotypes. Alongside this, evening owls were underperforming at work significantly more often than morning larks, with around 1 in 4 reporting work issues.  

These results are in line with previous research, but until the genetics of chronotypes and underlying mechanisms are revealed, it remains a correlation rather than a definite cause. The researchers suggest that chronotypes should be taken into account when planning work schedules to ensure the best health and performance from employees.  

Genetic chronotypes continue to be difficult to uncover, with genome studies constantly revealing more genetic variants that contribute to being a morning or evening person. A large-scale study in 2019 discovered various areas of the genome thought to be involved, whilst other studies have highlighted 22 variants currently known to be linked, which are involved in circadian rhythms and photoreception (perceiving light). Chronotypes are thought to be heritable, which means if your parents love the morning sun, you may be in luck for your future work performance.