Why We Sleep - Chapters 13-Conclusion Summary

The final section of the book covers the many ways that modern life has impacted how much we sleep. The invention of the light bulb has allowed us to restructure our daily schedules at the cost of our natural sleep cycles. Exposure to electric lights in the evening shifts the timing of our sleep schedules due to a delayed release of melatonin leading to later bedtimes. The more constant environmental temperatures afforded by central heating and cooling also alter our ability to sleep by reducing natural temperature changes that help aid in sleep. In order to fall asleep in the evening, your core body temperature must fall by 2-3 degrees Fahrenheit. For most people, an ideal ambient temperature for sleep in the evening is approximately 65 degrees Fahrenheit. Many people leave their thermostat set too high in the evening which makes it more difficult to fall asleep. When unable to sleep, both alcohol and sleeping pills may be sought out as sleep aids. Alcohol and sleeping pills may seem like they help with sleep, but in actuality both classes of drugs behave more like sedatives than sleep aids and prevent essential sleep cycles from occurring. Due to the dangers of sleeping pills, cognitive behavioral therapy and improving sleep hygiene are now recommended as first line treatment for insomnia over sleeping pills.

Throughout Why We Sleep the importance of sleep for all forms of health has been emphasized again and again, however many harmful societal ideas about sleep still persist. In the U.S. especially, there persists the problematic notion that the best employees work extremely long hours and reduce the amount of sleep they obtain in order to work even more hours. A lack of sleep reduces the competence and productivity of all levels of employees including managers. In order to improve employee well-being and productivity, companies should highlight the importance of sleep and even encourage employees to nap. The start times of schools in the U.S. represent another harmful disconnect between societal expectations and sleep science. The sleep cycles of teenagers are shifted later than adults, yet many schools have early start times that lead teenagers to miss out on REM sleep. When school’s shift to a later start time, student’s grades and SAT scores improve. In one Minnesota school, shifting the school start time from 7:25 to 8:30 am led to an almost 200 point cumulative increase in SAT scores across subjects. As the book closes, Dr. Walker argues that enacting policies that take sleep needs into account could improve the well-being of not only individual’s but the people around them in a wide range of fields from education to law enforcement and medicine.

Andi DeRogatis is a graduate student at UC Davis in the animal biology graduate group. She is currently studying how the avian immune system is influenced by the process of molt. She loves all things birds and is passionate about getting others excited about birds as well! You can follow her on Twitter @AndiDerogatis.

Lindsey Mooney is a graduate student in the UC Davis Psychology Department. You can follow her on Twitter @Linz_Mooney.

For more content from the UC Davis science communication group "Science Says", follow us on Twitter @SciSays.