We do a lot of things every day that most of us never stop to think about. Here we talk about three normal human behaviors – well, common at least – and provide some explanations for why we are the way we are.
What happens when we sleep walk, why are deadlines good for us, and how come we laugh? These are just some questions you might have on a daily basis, but we never bother to find the answers. Here we take a closer look at some of the idiosyncracies of ‘normal’ human behavior.
Remarkably little is known about sleep walking although 29.2% of the American population have reported sleep walking at some point in time.
In a recent study published in Sleep this week, 47% of the sleepwalkers reported nighttime injury, and an overwhelming majority only realised they’d been injured when they woke up later in the night or the next morning . Injuries included fractured skulls and legs, severe burns and deep lacerations – only to name a few.
Sleepwalkers also reported headaches four times more frequently than non-sleepwalkers, and migraines 10 times more often, as well as higher levels of chronic pain, depression, insomnia and daytime sleepiness.
What’s more, it seems that sleepwalking is on the rise in the general population, most likely due to the increased prescription of sedatives by physicians.
2. You like deadlines (even if you think you don’t)
Good resolutions are useless attempts to interfere with scientific laws. Their origin is pure vanity. Their result is absolutely nil. – Oscar Wilde, The Picture of Dorian Gray
In 2002, psychologists Dan Ariely and Klaus Wertenbroch ran experiment to see if students earn better grades if they set their own deadlines for handing in assignments .
We’re all familiar with the pressure to get a large assignment in on time – sleepless nights, too much coffee, and once in awhile an emotional breakdown.
Ariely and Wertenbroch split the class into three groups. The first group had freedom to choose their own schedule for turning in assignments. The second group was given a specific schedule: they had to finish each paper by a certain date, spread out over the term. The third group had to set deadlines in advance.
The first group with no deadlines generally got very little done, and handed in the papers late, and earned lower grades. The third group who set their own deadlines did much better in grades and timeline.
Yet the second group did the best – those who had the deadlines set by the class professor. Instead of endless choices for when to start writing the papers, external deadlines helped them plan better and avoid procrastination.
3. Laughing as a social lubricant
We laugh when things are funny, right? Well, scientists have reasons to believe this to not always be the case. Occasionally we’re surprised into laughing at something funny, but most laughter actually has little to do with humor. It’s an instinctual survival tool for social animals, to ensure we get along, but not an intellectual response to wit.
We first laugh as babies responding to physical contact. It has been thought that our brains have ancient wiring to produce laughter, so young animals learn to play with one another. The laughter stimulates euphoria circuits in the brain, and also works to reassure young animals that we’re playing, not fighting.
And one study even found that we’re more predisposed to laugh with people on the same level of the social hierarchy as us – with our co-workers, instead of our superiors, so we have allies in the workforce .
The Way We Are
As children, we ask our parents ‘Why is the sky blue’ or ‘Where do babies come from’, but only as we get older are we really equipped to understanding the complexities of human nature. Yet somehow we forget to ask. Try to think why people do the things they do more often, and trust me, you’ll come up with some interesting answers!
 Lopez R, Jaussent I, Dauvilliers Y. (2015) Pain in sleepwalking: a clinical enigma. SLEEP 38(11):1693–1698.
 Ariely D & Wertenbroch K. (2002) Procrastination, deadlines, and performance: Self-control by precommitment. Psychological Science 13(3): 219-224.
 Stillman T, Baumeister R & DeWall C (2007) What’s so funny about not having money? The effects of power on laughter. Personality and Social Psychology 33(11): 1547-1558.