The Relationship Between Sleep & Personality

We’ve all experienced it. That groggy, agitated feeling when we haven’t had sufficient sleep, the overwhelming desire to just shut out the rest of the world, avoid the general public and bury our heads on the nearest makeshift pillow. How often, however, do we consider how sleep affects our behaviour in this way?


Are we just tired or is there a tangible change in our brain function that causes our day-to-day life to play out differently than it should, which can adversely affect our happiness levels and behaviour.


It may sound pretty obvious, but sleep and mood are closely connected. Poor or inadequate sleep can cause irritability and stress, while healthy sleep can enhance our holistic well-being. While most of us are aware that our mood isn’t exactly fantastic when we’re tired and that most of us aren’t great to be around after a bad night’s rest, less of us are aware of the acute changes sleep deprivation causes to our brain’s wellbeing.


According to researchers at Harvard, chronic insomnia may increase the risk of developing a mood disorder, such as anxiety or depression.

The Well-Rested Brain vs. The Sleepy Brain


In 1959, New York DJ Peter Tripp pledged to stay awake for 200 hours for charity while continuing to host his radio show. A lack of sleep deprivation studies made the results of this stunt all the more fascinating. Tripp’s personality was normally described as upbeat positive and cheerful. By the third day, he was extremely irritable, insulting those closest to him without provocation. By the end of his feat, Tripp had begun hallucinating and exhibiting paranoid behaviours.


When we’re tired our tendency to enact fight or flight behaviours like stress, anger, or fear is increased without the relevant stimuli we would typically connect to these behaviours. These behaviours come from the amygdala, the emotional centre of our brain.


Typically, a well-rested brain will produce well-balanced, rational and healthy emotional responses to stimuli as the medial prefrontal cortex keeps the amygdala in check through a series of messages. Brain scans show that the connection between the amygdala and the prefrontal cortex is disrupted when our brain is sleep-deprived.


Without the prefrontal cortex keeping our brain in check, the amygdala is 60% more reactive, so otherwise innocuous daily interactions are more likely to result in a volatile response. Further, insomnia sufferers are five times more likely to suffer from depression and twenty times more likely to develop an anxiety disorder than individuals without insomnia.


It is, therefore, no surprise that 65% of adults who sleep 7 or more hours a night report having excellent mental health. Whereas adults that reported poor or average mental health sleep at roughly an hour less than their happier counterparts.

Brain Plasticity


Brain plasticity, also known as neuroplasticity, is a term that refers to the brain's ability to change and adapt as a result of an experience.


Studies show a direct relationship between sleep quality and our brain’s grey matter, the part of the brain responsible for muscle control, and sensory perception such as seeing, hearing, memory, emotions, speech, decision making, and self-control.


Poor sleep quality has been linked to the deterioration of grey matter areas in the brain leading to a number of problems including our ability to react appropriately to a situation.




It’s fair to say that the majority of us have become frustrated whilst sitting in traffic at some point in our lives. A night of quality sleep can be the difference between a rational response to this frustration and a bout of ‘road rage’.


On average, adults who sleep for 8 hours or more are more likely to practice defensive driving whereas drowsy drivers will have slowed reaction times, be more inclined to act aggressively to getting cut off or stuck in traffic.


When we consider that fatigue is a factor in 100,000 car crashes per year in the US, being alert and well-rested behind the wheel is even more of a necessity.


At Work


This one will come as no surprise. The well-rested brain is happier to be at work and well-equipped to deal with difficult co-workers, managers, or clients. Without adequate sleep, our ability to deal with unexpected outcomes and surprises falls dramatically.


Only 27% of adults who get over 8 hours of sleep report feeling overwhelmed at work in comparison to 40% of adults that get less than 8 hours of sleep a night.

With the Kids


If you’re a parent, then you’ve no doubt experienced the trauma of an overtired child that hasn’t had enough sleep. When children get the necessary rest required for their development they are better equipped to deal with emotional situations without feeling upset, irritable or responding aggressively.


88% of parents surveyed reported that their child’s mood is significantly impacted without quality sleep. Further, 81% of parents reported that a lack of sleep resulted in their children performing poorly at school.


Comparatively, when adults are well-rested, they tend to have healthier relationships with their children. 52% of adults that had slept for less than 8 hours reported yelling at their children.


With Your Spouse


Patience is a virtue and communication is the bedrock of a successful relationship. When we’re well-rested we’re able to better communicate with our partners and this leads to a more comforting environment.


A well-rested couple is more likely to exercise and feel physically healthy. The well-rested couple tends to have more energy and subsequently more sex and intimacy.


50% of couples lacking quality sleep reported losing patience with or yelling at their partners. Sleep-deprived partners also reported a lower libido and some men were found to have lower testosterone.

Final Thoughts


It’s clear to see that the quality of our sleep impacts our happiness in most of our daily activities.


People who have problems with sleep are at increased risk for developing emotional disorders, depression, and anxiety. Whereas people that get quality sleep each night are more likely to be happier and develop positive relations with their spouse, friends, coworkers, their children, and even strangers.


So, what are you waiting for? Turn on your blue light filter on all your devices at or around your usual dinner time, limit your exposure to screens around 1 to 1.5 hours before your scheduled bedtime, indulge in a cup of herbal tea and snuggle up for some ZZZs.

← Older Post Newer Post →



The Ultimate Guide to Getting the Best Sleep on Flights: Tips for a Comfortable Travel Experience

Travelling can be an exciting adventure, but long flights can often leave you feeling drained and unrested. Whether you’re jetting off on Cathay Pacific, HK...

Read more

Exploring the Benefits of Pink, Brown & White Noise for Better Sleep

Are you struggling with sleep or finding it hard to concentrate? The solution might be as simple as adjusting the sounds around you. Recent studies...

Read more