Researchers Identify Sleep As A Key Reason Why Personality Traits Predict Longevity

By Christian Jarrett

Your personality traits play an important part in how long you are likely to live, as much as, or even more than, other personal factors like your intelligence and your family’s economic background. Now a study in the Journal of Research in Personality has identified a key factor that mediates the personality-mortality link – sleep. Simply put, people with certain personality characteristics are more likely to sleep too little, or too much, or to experience greater sleepiness during the day, and in turn this raises their year-on-year risk of dying (too little or excess sleep, and poor quality sleep, have known links with various health risks, such as cardiovascular disease, depression and chronic inflammation).

“Sleep has been associated with both personality and longevity, yet [before now] no study has investigated whether sleep is a pathway linking personality to objective health outcomes,” say the researchers, led by Shantel Spears at West Virginia University.

The researchers used data collected from thousands of participants as part of the long-running National Survey of Midlife Development in the United States, including information on their personality traits recorded in 1995-1996, and information on their sleep duration and sleep quality collected in 2004-2006. Nearly 4000 participants provided data at both these time points, and the researchers then used national records to see which of them had died and when, up to October, 2015.

As expected, based on the known importance of sleep to health, the research showed that too little or too much sleep was associated with increased risk of dying – approximately 65 minutes more than, or under, the average nightly sleep duration (7 hours in this sample) was associated with a 10 per cent increased risk of dying over the course of the study.

Turning to personality, and consistent with many prior studies, participants who scored lower on trait conscientiousness were more likely to die before the end of the research period, and Spears’ team established that this was explained in part by these people getting less sleep, on average, and feeling less rested during the day (a mark of poorer sleep quality). Although the study didn’t look into why exactly people low in conscientiousness were getting less sleep, one can imagine they engage in more bedtime procrastination, and generally struggle to establish a healthy bedtime routine.

Similarly, high scorers on trait neuroticism were indirectly at greater risk of dying because of their lower and higher than average amounts of sleep, and their on-average greater feelings of fatigue in the daytime. Again, one can speculate that these folk, who have lower moods and more worry, might struggle to get to sleep or to get up promptly in the morning.

Lower scores on extraversion were indirectly linked with increased risk of death, thanks to an association with greater daytime feelings of fatigue (perhaps extraverts’ greater daytime activity levels makes it easier for them to get a satisfying night’s sleep, but this is speculation). Most surprising – given prior research findings have not identified this trait as being relevant to sleep – was the indirect link between higher trait agreeableness and risk of dying, explained by these people having less sleep and more daytime fatigue; it’s not clear why this might be.

Previous research had already established that personality predicts longevity because of its association with various health behaviours, such as more conscientious people being less likely to smoke, or drink and eat to excess. However, much of the personality-linked variance in risk of dying has remained unexplained, and this study now identifies too little or too much sleep (and feeling insufficiently rested during the day) as other important factors. “Our findings suggest that short and long sleep duration and daytime dysfunction may be important pathways linking aspects of personality to reduced life expectancy,” the researchers said.

The research has some important limitations including the participants being mostly white and highly educated; the reliance on a short self-report test of personality; and the subjective measure of sleep being based on time spent in bed rather being asleep per se. Nonetheless, if the results can be replicated, they raise some important implications for public health, suggesting that personality screening could be used to identify those people – especially high scorers in neuroticism and low scorers in conscientiousness – most likely to benefit from interventions aimed at improving sleep. “Alternatively,” the researchers said, “changing these aspects of personality could improve sleep for these individuals, enhancing their health and longevity”.

Sleep: A Pathway Linking Personality to Mortality Risk

Christian Jarrett (@Psych_Writer) is Editor of BPS Research Digest and the author of a forthcoming book on personality change

23 thoughts on “Researchers Identify Sleep As A Key Reason Why Personality Traits Predict Longevity”

  1. I am in my 60s never in my intier life ,since birth, premature ,blue baby, have I ever had a NORMAL sleep hygiene. 50 Years of zero Quality of sleep. Grand Mall siezurs, as a result.TOP SLEEP EXPERTS AT STANFRD UNIVERSITY. Thier Sleep Clinic in REDWOOD CITY CA .TOLD ME I SHOULD ALREADY BE DEAD !!! WITH TREATMENTS, I GET FROM 30% QUALITY OF SLEEP TO A MAX OF 65% QTY OF SLEEP. ECONOMY OF TEXTING HERE. WOULD LOVE YO BE APART OF A RESEARCH PROGRAM . I AM A VERY COMPLICATED CASE. TWO YRS ago ,by THREAT OF SUICIDE, I DEMANDED A TOP QUALITY SLEEP STUDY. So I GOT ONE. It took, TWO YEARS TO FIGURE OUT ALL OF MY SLEEP ISSUES. All SERIOUSE ONE’S: RETENTION OF CO2 LETHALY SO, ABNORMAL REM STRUCTURE. RESTLESSNESS LEG SYNDROM OF SORTS ACUTE OBSTRUCTIVE SLEEP APNEA. DIABETIC AS A RESULT. SO WHY AM I STILL A LIVE??????? STILL STRUGGLING. THANK. You all , FOR YOUR GOOD WORK ETC. PAUL (Dyslexia) and (L. D ) with a college graduate b+ average I. Q 97. Paul.

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    1. Hey man, I just wanted to tell you — I’m really sorry this has affected your life the way it has. Good for you, for continuing to advocate for yourself, and for working to make your situation better! I too am a problem sleeper, though — it sounds like — nowhere near as bad as you. So … hugs to you man. May you continue to seek out (and finally GET) the help you need.

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    2. You’re “still alive” because these factors only influence odds of deviation of lifespan that is unique to each individual, they are not some kind of hard formula of exact year of death.

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  2. I was referred to sleep lab, too! But, I already had an EEG!
    I found out from furthercreadi g thst sleep disorders can be associated to lupus, and systemic lupus erythmatosis.
    I had to remove caffiene from.my diet, too!
    I have a cardiac defect! I wrote Stanfird, but they didn’t email me back!

    If you see my picture, name on Quorum Digest, its not me! Someone was using my picture, email address! There may be other incidences of that as I was identity thefted by China, in a cyber-attack!

    Susan Berg

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