We all know that there's more dividing night owls and early birds than their bedtimes, but those differences could just be based on late sleepers we knew in college, right? The latest video from AsapSCIENCE examines these differences closely, bringing up inherent traits like productivity and creativity that depend much more on your sleep schedule than you'd think. Not so surprisingly, those who are early to bed and early to rise have been found to be more productive, as well as proactive, optimistic, and less likely to have depression or an addiction. Meanwhile, those who sleep the day away are likely to have higher cognitive abilities, take risks more willingly, and be more creative. Many of these differences are more visible to us thanks to the type of schedule that most of the working world keeps — office hours naturally favor early risers over late sleepers. So, when the latter is already off their preferred sleep schedule, they end up feeling groggier than usual, and traits like productivity and optimism are more obvious in the former. However, studies have found physical differences in the brains of late sleepers and early risers, too, specifically in the amount of white matter, which aids in communication between neurons. Late sleepers just don't have as much, and as a result, have fewer pathways in their brains for serotonin and dopamine (which the video refers to as "feel-good hormones") to travel through. The mental effects of various sleep schedules are a result of both our society and biology — most of your sleeping habits have actually been shaped by evolution. In other words, whether you have to drag yourself through the mornings or you start lagging by the afternoon, you have plenty of options for where to place the blame. Check out the full video and be sure to catch its explanation of social jet lag, a.k.a. what you dealt with the entire holiday season.