Night owls really are different

I often hear people say that they are either a morning person or a night owl. I am the latter. My most intense creative and philosophical thoughts occur to me after 9:00 pm. This presents some challenges when I work jobs where I have to be up and going early in the morning. Now, I should clarify that early in the morning for me counts as anything in the 7-9 am range. I’ve also wondered how I would do in a triathlon, if I could do it in the late afternoon or evening.

There is a fair amount of research on the topic that indicates that factors like genetics have an important role to play. So if being a night owl is in my genes what does that mean for me?

According to one study at the University of Chicago, women who are night owls tend to have higher cortisol levels, and exhibit greater risk-taking behaviour than women who are morning people, but similar levels to men. Although, another study that did not distinguish between male and female found higher cortisol levels in early risers.

Another study, conducted by researchers at the University of Alberta found that morning people’s brains were most excitable at 9 am; while evening people’s brains were most excitable at 9 pm. Other findings indicate that while a morning person’s maximum amount of force that they can produce stays the same all day, an evening person’s increases. Perhaps I do need to find an evening triathlon. But for both groups the excitability of reflex pathways increased throughout the day.

The relationship between your prime time of day and your intelligence has also been examined. A meta-analysis looked at a number of studies that examined the relationships between your preferred time of day and your cognitive ability: being a night person was positively related to cognitive ability. And your preferred time of day and your academic achievement: being a night person is negatively related to academic achievement. The opposite is true for the morning person. To me, this definitely has implications for school times.

Here’s the findings that I find most interesting from my current perspective though. You have two main types of neurons in your body: myelinated and unmyelinated. Usually, these are referred to as white matter and grey matter respectively. The integrity of the white matter in your brain is essential for brain function. In a recent study (2014), researchers found that people show distinct differences in the white matter of their brain based on what time of day they are most effective. Night owls, who show less integrity in their white matter show a form of chronic jet lag, greater vulnerability to depression, and greater consumption of addictive substances, primarily nicotine and alcohol. While I personally do not suffer from depression, and my addictive behaviours tend to be things like exercise, I get the chronic jet lag. The authors of this study suggest that whenever possible, work schedules should fit with your natural schedule, in order to avoid the negative consequences of someone who is a night person, being forced to be on their game first thing in the morning.

So, it you are a morning person, or a night person, be aware that there are consequences of that predisposition. And if you can find ways to make your schedule fit your natural body clock, it will probably be better for all involved.

Maestripieri, D. Night owl women are similar to men in their relationship orientation, risk-taking propensities, and cortisol levels: Implications for the adaptive significance and evolution of eveningness. Evolutionary Psychology 12(1): 130-147.

University of Alberta. (2009, June 24). Morning People And Night Owls Show Different Brain Function. ScienceDaily. Retrieved December 9, 2014 from http://www.sciencedaily.com/releases/2009/06/090623150621.htm

Rosenberg, J., Maximov, I., Reske, M., Grinber, F., and Shah, J. (2014). “Early to bed, early to rise”: Diffusion tensor imaging identifies chronotype-specificity. NeuroImage, 84(1), 428-434.

Preckel, F., Lipnevich, A., Schneider, S., & Roberts, R. (2011). Chronotype, cognitive abilities, and academic achievement: A meta-analytic investigation. Learning and Individual Differences, 21(5), 483-492.