When Stravinsky’s ballet “The Rite of Spring” debuted in 1913 in Paris it caused a riot. The music was so complex and novel that the audience didn’t know how to react. They became agitated, jeered, argued amongst themselves and eventually became violent. However, by the 1920’s the Rite of Spring was well accepted and now it is considered one of the greatest works of the 20th century. When Impressionism was introduced in the late 19th century it was not well received. The term was actually meant to be a derisive of the movement. These days, the Impressionist rooms are often the most popular and crowded at Art Museums. There was strong opposition to Maya Lin’s design for the Vietnam Memorial in 1981. She actually had to defend it before the US Congress and fought to keep it from being changed. Now it is considered one of the most beautiful monuments in Washington D.C. There are countless other examples of icons of beauty that were initially considered offensive or ugly. I think this is perfectly consistent with what we know about neuroscience.
As I wrote recently in my post on neural coding, there are neurons in the brain that become active when any object or concept is experienced either through the senses or through recollection. These neurons have what are called receptive fields, which basically means the set of stimuli or conditions that activate a given neuron. Generally, for each stimulus, there are a large number of neurons that become activated but each neuron will have in general a different receptive field from any other neuron. Hence, there are many neurons with overlapping but nonidentical receptive fields. Each pool of neurons with overlapping receptive fields can be thought to code a class of related objects. For example, there are neurons that code for faces, houses, tools, animals, etc. These pools are partially innate and partially subject to modification through neural plasticity.
It seems that beauty may be indicated by the fraction of neurons in a pool with overlapping receptive fields that are activated by a given object. If a large number are activated then this would be considered beautiful. The objects that would maximally excite a pool of neurons would correspond in essence to the idealization of that object. For certain objects, this could be represented by the average. For example, this has been shown to be true for faces (the Australian radio program The Science Show gave a nice summary of this last year). Neural plasticity through a Hebbian learning rule gives a plausible explanation for why an average would become the standard of beauty. As a person is exposed to various faces, each will excite a different fraction of the face neurons. Neurons that are activated together could then strengthen connections between them so that they are more likely to fire together (i.e. neurons that fire together wire together). Hence, it is plausible that the average face would then excite the most number of neurons (for large enough numbers of neurons and faces the mode and average of neural responses would be similar). This gives a plausible explanation for why there is a large consensus for standards of beauty that seem to be somewhat but not completely time and culturally dependent.
By the same reasoning, stimuli that activate only a small fraction of neurons would be considered ugly. A completely novel work of art would not have a dedicated set of neurons to represent it. Thus, it would only partially excite a number of neurons from various objects corresponding to elements that make up the object or objects it resembles. It would thus give an “ugly signal” in multiple dimensions. However, upon further exposure to this object, a new set of neurons with a receptive field corresponding to this object may be created through neural plasticity. In time, the formally ugly object will maximally excite a new pool of neurons and thus be considered beautiful. This is not to say that all ugly and horrendous things could be eventually viewed as beautiful. Things that are familiar but ugly probably get coded that way and remain ugly. It is only novel objects that have the potential to become beautiful.
Artists in the twentieth century grabbed onto this concept and took it to the extreme. That is why each new art movement became less and less attached to classical forms. In visual arts, after Impressionism came Expressionism, Cubism, Dadaism, Surrealism, Minimalism, and so forth. Each one challenging the past forms. Music in the twentieth century abandoned the traditional tonal scale and moved to twelve tone and atonal forms. However, I think what happened is that the cultural elite simply split off from the general public. It really takes a lot of exposure to like twelve tone music. I for one, never really took to it. I think the one art form where there the progression from ugly to beautiful is most likely to be universal is architecture because everyone is forced to look at the same buildings over and over again.