Many of us have heard the term "night owl," however do genetics contribute to the late night behavior? Staying up late and having trouble waking up is often diagnosed as delayed sleep phase disorder (DSPD) according to sleep clinicians. It is estimated to affect about 15% of the population in the United States. People with DSPD have a delayed circadian rhythm, which in your internal clock aligning with the physiology of the environment. People's circadian rhythm have a clear genetic basis that has remained the same over the course of evolutionary history. In cases of people with DSPD, there is a large part of the protein expressed by the gene to be missing. This change makes the inhibitor hyperactive, causing it to repress the activators for too long and extend the circadian cycle by at least a half an hour if not more.
Fortunately, I am not part of the 15% of night owls. In fact, I am the complete opposite. I have a very hard time staying up late, and find myself fatigued throughout the day. I am a very early riser, having no trouble at all hopping out of bed as soon as my alarm sounds. However, I must do farther research on this topic, as it pertains to my boyfriend. He on the other hand, cannot fall asleep early, and cannot wake up at a decent hour. Now he can make the valid argument that it is not laziness, but genetics causing this behavior!