Is beauty simply in the eye of the beholder, or do all the beholders’ brains have something in common? Is there an objective side to beauty? Plato certainly seemed to think so. His view was that beauty was an inherent property that all beautiful objects possess, irrespective of whether someone likes it or not.
To him, beauty in the world stemmed from an ideal version of Beauty that real objects can only aspire to. A biologist might instead suggest that the objective side of beauty stems from built-in predispositions for certain features, colours, shapes or proportions.
The opposing view is that art is a fully subjective enterprise and our preferences are shaped by our values and experiences. The real answer is likely to lie somewhere in the middle – after all, art students learn basic common skills such as proportion, perspective and symmetry before embarking on their own stylistic journeys.
Artists, critics and gallery visitors can argue about this question all they like, but some clearer answers have now emerged from three researchers in Italy, arguably the home of the some of the world’s most beautiful art. Cinzia Di Dio, Emiliano Macaluso and Giacomo Rizzolatti from the University of Parma have brought the tools of the modern neuroscientist into the debate.
The golden ratio
They showed images of 15 masterpiece sculptures from the Classical and Renaissance periods, to 14 regular people who had no experience of art criticism. As they looked at the pictures, the scientists scanned their brains with a technique called functional magnetic resonance imaging (fMRI).
Some of the images were subtly altered. In their original form (middle statue below), the sculptures were proportioned according to the Golden Ratio, the ratio of lengths that the ancient Greeks thought was most aesthetically pleasing. It works out to about 1.16 and turns up all over the place in classical art and architecture.
For example, in Doryphoros by Polykleitos, the ratio between the distances from navel to knee and from navel to sole is 1.16. The ratio of the distances from navel to sole and from navel to head is also 1.16.
In the altered versions, the images had different proportions but were the same in every other respect. Their trunks or legs were stretched enough to throw their golden proportions out of kilter, but not enough for the viewers to notice that consciously twig that something was wrong.Objective vs. subjective
At first, the researchers simply asked their subjects to look at the images as if they were in a museum, without having to perform any complicated task. On average, they gave the original images positive reviews 76% of the time, but only liked the distorted images 63% of the time.
The golden ratios of the original images strongly activated neurons in a part of the brain called the insula, while the altered images did not. The insula is involved in the feeling of emotions and the research trio speculate that it generates the positive feelings that accompany beautiful images.
To them, these results show that beauty is at least partially objective. They suggest that groups of neurons in the brain are trained to respond to different characteristics, such as proportion, and have certain preferences. When the signals from these individual processing centres arrive at the insula together, it generates a positive feeling – a sense of beauty.
But the team also showed that subjectivity still exerts a sizeable influence. They repeated their experiment but asked the viewers to judge the images, generally in terms of aesthetics and specifically based on their proportions.
They compared their brain scans as they responded to images that were consistently praised for their beauty with those that were constantly denounced for their ugliness. This time, the insula didn’t matter. Instead, the beautiful images activated the amygdala, a region that links learned information with emotions.
Together, these results strongly argue that even an abstract concept like beauty is the product of the very tangible and physical matter of the brain. Finding beauty in art is the result of a neural agreement between two parts of the brain that respectively govern the subjective and objective sides.
When you stare at a painting, scene or object, the neurons that report in to your insula set an objective standard for assessing beauty. However, those of the amygdala draw on your emotional experiences to add a subjective colour to your final reaction.
Di Dio, Macaluso and Rizzolatti end their paper by speculating that the objective side, driven by our biology, may influence the lasting quality of certain pieces of art. New trends arise because they appeal to either biological preferences or simply to novelty or fashion. But as the latter eventually fades and wanes, future generations may have only the former to base their judgments on.
More on the insula: The insula – the brain’s cigarette addiction centre
Di Dio, C., Macaluso, E., Rizzolatti , G. (2007). The Golden Beauty: brain response to Classical and Renaissance sculptures. PLoS one, 2(11), e1201.
*As a side note, the researchers also found that many of the images activated the medial temporal and medial superior temporal cortex, parts of the brain involved in detecting movement. Other studies have found that these regions respond to still images that imply movement and the authors speculate that activity here accounts for the powerful sense of dynamism that some works of art can invoke.