Research shows that preferences for certain sleeping positions change with age. The older you are, the less likely you are to change position or to move in your sleep. Children spend almost equal amounts of time sleeping on their backs, sides and stomachs, while adults show a preference for sleeping on their side with only a few choosing to sleep on their stomachs. There also appears to be a preference for sleeping on the right side as we get older.
Across all age groups, the foetal position is the most popular - lying on the side with arms and legs bent. This most popular sleeping position may have evolved for health reasons as recent research indicates lying on your side optimises waste removal from the brain during sleep. It also may help to reduce bodily discomfort.
Sleeping in a position that isn’t comfortable or disrupts your sleep can have an effect on personality and mood as if you have poor quality sleep you may lack motivation, experience concentration problems and feel more irritable the next day. This can have consequences for your social and family relationships, your work or academic achievement. Inadequate sleep may also make you less social and this may impact negatively on your mood. Viewed in the long term you can see how these factors can affect your personality.
Although many articles claim that sleeping positions reveal aspects of a person’s personality there is no published scientific evidence to back this up. These articles claim, amongst other things, that if you sleep in the foetal position you have a tough exterior but are warm and open-hearted whereas if you have a preference for sleeping on your side with arms outstretched you are perceived as open but are actually suspicious.
The source of these claims comes from sleep expert, Dr Chris Idzikowski, who conducted a survey on behalf of a PR company. Although his initial survey showed some interesting findings regarding sleeping positions and personality that lead to the media stories, he has not been able to replicate the findings in further surveys and so the work remains unpublished. “The original study was never more than a fun study,” he states, “but was successfully a vehicle for sleep positions and health messages: sleeping on one’s back leads to reflux, snoring, even an increased incidence of sleep paralysis.”
The preference for side sleeping with age is likely to be due to comfort rather than personality as this position eases flexibility, and digestion and breathing problems. Additional effort is needed for breathing in other positions and the spinal cord becomes less flexible with age. Studies have identified bodily discomfort as a major factor affecting sleep quality and this appears to increase with age. Investing in a mattress to suit personal preferences and finding a sleeping position to suit you may help to reduce any bodily discomfort that contributes towards poor sleep.