For the Love of Symmetry

 Did you know that humans and animals strongly prefer symmetry?

Decorative window in Bali

Both animals and human have symmetrical features about a plane running from head to toe (or tail, for that matter). This is called bilateral symmetry.

There is a strong correlation between body symmetry and preferential mate selection. Female birds choose males that display the most symmetrical sexual characteristics. For example, peahens prefer peacocks with the largest and most symmetrical tail feathers.

Lighthouse, Puerto Rico

Castle window, Puerto Rico

River bridge, West Virginia

Humans show similar patterns. The more symmetrical a human face, the more we describe it as beautiful. Even 4-month old babies stare longer at more symmetrical faces than less symmetrical ones.

Sun sculpture, Albuquerque

In addition to the beauty advantage, researchers found correlations between body symmetry and health: men with asymmetric faces were more likely to suffer from depression, anxiety, headaches and stomach problems. Women with facial asymmetry were likely to be less healthy and more prone to emotional instability and depression.

Scottish mustards

Fossils show that bilateral symmetry was prevalent in animals as early as 500 million years ago.  So there must be a very strong evolutionary advantage to this symmetrical blueprint.  Most flowers seem to favor a symmetrical pattern.  Trees tend to grow in symmetrical shapes unless something distorts their growth pattern.

Pink tulip

Symmetry is also omnipresent in the physical sciences and the laws that govern our universe.

Gazebo in Scotland

The mystery continues….

Navajo blanket

While my photos do not necessarily illustrate the text by showing images of animals and people, they express a wide range of human creativity and symmetrical preferences in our artistic and architectural creations.

If you are interested in a more scientific treatise on symmetry, you may want to read Mario Livio’s “The Equation That Couldn’t Be Solved.” In his book, he explores symmetry in a wide variety of disciplines, from biology and physics to music and the visual arts.

The Daily Post’s Weekly Photo Challenge is Symmetry.