Do you have a best side? Is symmetry tantamount to sexiness?
A project by US fashion photographer Alex John Beck challenges the belief that balance is more beautiful.
In a series of portraits, Beck made symmetrical versions of the right and left sides of the model's face. The result - the contrasting characters that can exist in one face - is arresting.
"We give weight to each side of the face, making two faces from one face, two faces from one moment, captured by one photograph," Beck explains.
"The less symmetrical they are initially, the more different the characters suggested by each face. The more symmetrical faces betray their owners more subtly, however, one side proves clearer, the other more inward looking.
"Maybe a person who knows them in real life recognises one portrait and not the other. Regardless, each is always present, though as a half, and each face is valid.
"So, when the owner of the face thinks they present an expression of positivity and openness, the other side has other ideas, frowning."
But, asymmetry can equate to character and complexity and therefore be equally compelling, Beck argues.
Perhaps true beauty lies in between perfection and our peccadillos.
"I think they lack character - beauty is more based on character than an arbitrary data point," Beck told Time of his symmetrical portraits.
"Humanity is messy and should remain as such. I, for one, am not a fan of centre-parting, for example. And even the greatest tennis players favour one arm."
He believes that seeing the left and right side-by-side in this way, instead of showing the original portrait as well, is revealing.
Our eyes can express incongruity in the way we feel, for instance.
"One side is completely present and alert and getting ready and interested, and the other side is half asleep," he observes of a portrait.
It is not the first time a project like this has been done.
In 2010, Australian photographer Julian Wolkenstein began a similar project.
"It is as much about beauty as self-reflection - what beauty is to each person," Wolkenstein says. "It looks at how you see yourself - if you look in a mirror you are reversed, this is how we normally see ourselves daily."
He is unconcerned that Beck's project is virtually identical to his own.
"I have seen other people do similar things after me and there were others before me, so I would not claim the idea," says Wolkenstein, who now runs a website and an app called Echoism where people can try out their own different sides for size.
"Echoism has had over 70,000 uploads since November 2011, when the app went live," he says. "According to Google analytics it's reached 192 countries in the world."
He points out that while he is thrilled by the response, the site is more "about questioning a beauty myth" than any attempt at a scientific thesis on beauty and perception.
"I am not commenting on the beauty of symmetry as such, more that we have a notion of our image and what happens when we abstract this - do we see ourselves differently?"
- Sydney Morning Herald