When Alice asked her cat if the milk in the looking glass tastes the same as the milk in her dish, author and mathematician Lewis Carol was using a surprisingly accurate analogy.

At a molecular level, the vast majority of substances exhibit little symmetry. Instead atoms are combined in structures that curl either one way or another. Look through a microscope at a non-organic substance like a lump of granite and you’ll see a mixture of left or right spirals, but examine any living thing and they all curl left. Bacteria, pollen, humans, trees, bananas and milk… everything. Nature is ‘left-handed’.

Despite nature’s left bent, scientists are able to synthesize right-handed or mirror versions of natural molecules. The spearmint flavor that Wrigley’s use on their chewing gum is a manufactured mirror image of the caraway seed molecule.

But before hypothesizing whether Alice’s mirror milk would taste of strawberries or anchovies it’s worth reflecting upon the sinister potential of buggering with nature’s curl.

In 1961 when 12,000 babies were born without arms and legs and Thalidomide was withdrawn from the market, nobody understood how a perfectly safe sedative could do so much damage. Subsequent analysis showed that at some point after its introduction onto the market, the lefty molecules that made the drug so effective had mutated into a highly toxic mirror image.

So mirrors can have negative effects at the molecular level, but what happens when we gaze at our reflection? Do we like what we see?

In their Symmetry podcast, the Radiolab team told the story of a young man whose image of himself (at worst – normal, at best – cool), was challenged throughout his childhood and adolescence by bullies that physically abused him, and society that shunned him.

It followed him whichever school he attended, in each neighborhood he lived, and even to the seaside town him parents took him each summer.

His puzzlement grew when, during the hiring process for a part-time job, he was photographed and was presented with 4 identical copies of a face that looked, well, wrong.

“Who’s that dork?” he wondered, as he stared at a picture that appeared to be a nerdy, unattractive and uncool version of himself, and he realized for the first time that this was how others saw him – not the mirror image he stared at every morning, but the flip side – the real him.

Looking closely, the only physical difference seemed to be the hair that parted from the left in the mirror, and from the right in the photo. Could that be it, he thought? just the hair?

Well, needless to say, he changed the parting and changed his life. School, work, and even the summer holiday kids invited him into their circle, treated him with respect, bought him beers… Literally overnight his life had turned around.

You can see the effect of such a switch in the photos below. The first is of Abe Lincoln as we know him and the other as he would see himself every morning as he shaved :

The obvious interpretation is that Abe’s characteristic face is so well known to us that any interference would look out of place, but the reality appears to be deeper.  Humans, it seems, favor one side of our faces over the other.  When we smile, or frown we do so slightly more on the left side, and a parting that emphasizes or draws the attention to that side renders us more animated, characterful and interesting than we would be perceived had we a parting on the right.

It is no surprise therefore to discover that Clark Kent parts his hair on the right, while Superman parts it on the left.  No mirrors at work here – it seems that Hollywood has at least one behavioral psychologist actively consulting their stylist team.  What is perhaps more of a shock – if it can be believed, is that following Carter’s 1970’s call for national unity for which he attracted almost universal criticism for his weakness and lack of presidential charisma, the young man from Radiolab wrote to him suggesting that he change the parting in his hair from right to left.

Six weeks later during Another address to the nation, the world’s press and especially John Walter was shocked to see that the president was now parting his hair on the other side!

All this would be less painful for me if my hair wasn’t forced into a right-hand part by an uncontrollable cow’s lick inherited from my mother…