When I read this I thought: well, that’s obvious – it’s because of the sudden rush of blood to the face. The magazine however, explained it from a different perspective. Blushing, according to the article, is one human expression that Darwin struggled to explain. He pointed out that while humans of all races blush, animals and primates don’t. So why would we evolve a mechanism that would put us at a social disadvantage since blushing acts as an indicator that we have lied or cheated? Several theories were suggested: one is that it started as an appeasement ritual enabling us to show a dominant member of a group that we acquiesce to his authority. Later, however, this became associated with guilt, embarrassment and shame. Blushing was evolutionarily important because it acted as a lie detector i.e. if you ask someone about infidelity they couldn’t lie without blushing.
Thus, once blushing became associated with embarrassment it conferred an advantage to people who blushed because humans are less likely to trust someone who never gets ashamed and mate with them.
No other species has teenagers - meaning the transition from juvenile to adult form is smooth whereas for humans we have the awkward years from 13-19 (less for some). Of all the explanations they gave the one that seemed reasonable to me was the one they gathered from neurobiology and brain imaging. Their studies showed a wholesale reorganization of the brain during these years, implying that adolescence is less about achieving sexual maturity than about developing a mind capable of dealing with the psychological and social issues that face man and draw a line between humans and animals.
Another, more amusing explanation was given by anthropologist Barry Bogins of Loughborough University, UK. He stated that boys are sexually mature long before they develop their manly physique. This allows teenage boys to acquire sexually selected attributes that appease potential mates (e.g. humor, artistic talent etc) in a safe environment because their boyish outlook does not serve as a threat to older men.
Almost everybody at some point in their life has done something superstitious. Performing badly on an exam because you didn’t have your lucky pen or wearing a green shirt right before a match are the kinds of superstitions a great many people have even without little rational explanation.
According to Bruce Hood at the University of Bristol, our brains are designed to detect order and patterns in our environment. Also, we tend to associate causes to preceding events e.g. you may associate the food you had last night to the cause of you catching the flu although that may not be the case. This quest for seeing patterns and inferring causes makes us susceptible to superstition.
Superstitious beliefs can be thought to be favored evolutionarily as well. As stated in the article: “our ancestors would not have lasted long if they had assumed that a rustle in the grass was caused by a wind when there was even a small chance it was a lion. And it is worth making false-positive mistakes to get these relationships right.” Religion offers another evolutionary benefit of superstition. This is achieved by humans beings’ desire to believe that supernatural beings can influence their fate. Hood states: “There are few atheists in a plane plummeting from 30,000 feet.”
Apparently, “kissing – in the amorous lip-locking sense - is not practiced in all cultures, so the urge to pucker up cannot be in our genes.” Yet we wonder why exchanging spit with your loved one feels so darn good.
One theory was that kissing has its root in foraging (act of searching for food). The story is that our ancestors were attracted to red ripe fruit used this as a template for sexual attraction (red lips).
While these theories do not seem altogether too valid to me, the physiology did a good job at explaining the science behind kissing. Our lips are among the most sensitive parts of our body, packed with sensory neurons linked to the pleasure centers in the brain. In addition, kissing reduces the stress hormone cortisol and increases release of feel-good hormone oxytocin.
Kissing is also used to assess compatibility with a male. According to recent studies we are attracted to smell of sweat from people having the most dissimilar immune system than ourselves (to produce healthy offspring). Kissing enables us to get close enough to sniff that out.
It is not understood why people would eat their own snot given that it has no nutritional value. It is suggested that ingesting nasal detritus i.e. boogers helps build a healthy immune response - since a lack of exposure to infectious agents makes us susceptible to allergic diseases. The only research that holds some ground dates back to 1966 that concluded that people who eat their bogeys found them “tasty”.
For all those wondering what the other five things were: dreams, altruism, pubic hair, art and laughter.