Hannah Copsey discusses new research of the benefits of a quick forty winks

Carrie Snow tells us that every bad day can be put to rights with a nap, but how much of our napping habits are controlled by genetics? And how much of afternoon napping is a behavioural choice?

Scientists at Massachusetts General Hospital (MGH) have identified regions of genes which control our tendencies to take naps during the day. Researchers have previously studied other aspects of sleep, including the genes which distinguish ‘early risers’ from ‘night-owls’. In the present study, individuals’ complete genomes were scanned to identify genes associated with daytime napping.

During the study, participants were asked how often they take naps during the day, whether that be ‘usually’, ‘sometimes’ or ‘never/rarely’. The researchers then combined this information with data from the UK BioBank, a database containing genetic information from almost half a million UK individuals.  The study identified 123 regions of human genome associated with napping, with several genes being linked to a neuropeptide orexin, which is involved in wakefulness.

Upon further analysis of the data, three mechanisms were proposed which may promote daytime napping. Firstly, some individuals may simply require more sleep than others. Alternatively, taking naps during the day may make up for a poor-quality night’s sleep, or those who wake up early may use a nap to catch up on sleep.

This study demonstrates that daytime napping is biologically driven and not simply a product of our environment, so taking a short power-nap when needed may not be so unproductive after all!