The New Scientist magazine compiled a list of the everyday aspects of life
which continue to confound the world’s greatest brains, including the reasons
behind kissing, blushing and even picking your nose.
An editorial in the publication said: “There is nothing more fascinating to most
of us than ourselves.
“So it is hardly surprising that we have expended large amounts of effort trying
to get to the bottom of what it means to be human.
“What is surprising is that there are so many traits that remain enigmatic.
“These range from the sublime, such as art, dreaming and altruism, to the
ridiculous, think pubic hair, blushing and nose-picking.
“They may seem quirky but the best explanations for them often have profound
Here are some theories on why we do those things we do and some of the problems:
1 – Blushing: Charles Darwin struggled to explain why evolution made us turn red
when we lie, which alerts others. However, some think it may help diffuse
confrontation or foster intimacy by revealing weakness.
2 – Laughter: mood-improving endorphins are released when we laugh, which seems
an obvious reason to do it but a 10-year study muddied the waters when it found
more laughter is produced by banal comments than jokes.
3 – Kissing: the explanation for kissing is unlikely to be genetic as not all
human societies do it. There are theories that it is associated with memories of
breastfeeding and that ancient humans weaned their children by feeding them from
their mouths, which reinforced the link between sharing saliva and pleasure.
4 – Dreaming: Sigmund Freud’s theory of dreams expressing our subconscious
desires have been generally discredited and it is recognised that they help us
process emotions, but the reason why we see such strange visions has not been
5 – Superstition: unusual but reassuring habits make no evolutionary sense;
however, ancient humans would have benefited from not dismissing a lion’s rustle
in the grass as a gust of wind. Religion seems to tap into this impulse.
6 – Picking your nose: the unappealing but common habit of ingesting ‘nasal
detritus’ offers almost no nutritional benefit, so why do a quarter of teenagers
do it, on average four times a day? Some think it boosts the immune system.
7 – Adolescence: no other animal undergoes the stroppy, unpredictable teenage
years. Some suggest it helps our large brain reorganise itself before adulthood
or that it allows experimentation in behaviour before the responsibility of
8 – Altruism: giving things away with no certain return is odd behaviour in
evolutionary terms. It may help with group bonding or simply give pleasure.
9 – Art: painting, dance, sculpture and music could all be the human equivalent
of a peacock’s tail in showing what a good potential mate someone is. However,
it could also be a tool for spreading knowledge or sharing experience.
10 – Body hair: fine hair on the body and thick hair on the genitals is the
opposite of what occurs in primates, our close animal relatives. Suggested
reasons for pubic hair include a role in radiating scent, providing warmth or
even protecting from chafing.