Editors’ note: The following is an excerpt from The Shape of Green: Aesthetics, Ecology, and Design (Island Press).In iconic nature scenes, one shape is ubiquitous: the tree.
Mathematicians categorize fractals by their density (D) on a scale of 1 to 2, 1 being a flat line and 2 being complete fill; environmentally, the open ocean approximates D=1, while a thick jungle approaches D=2. Experiments by physicist Richard Taylor and others repeatedly reveal that a large majority of people (94 percent in Taylor’s experiments) prefer a density around 1.3 or 1.4, which matches acacia- and savanna-like images, including the abstract diagrams from the Wise experiment. The theory is that a preference for these kinds of fractal images is genetically imprinted at a density we associate with the optimal environment for survival--too sparse means not enough sustenance, and too dense means not enough opportunity for surveillance. Using eye-tracking techniques, Taylor also has shown that we tend to scan our surroundings with a fractal pattern approximating the preferred density, even when that pattern doesn’t exist in the visual field. We seek out the desired imagery everywhere we look.