bilateral symmetry

オリンピックが終わったのでテレビ・録画を見る時間が平常に戻れます。　さて、Nicholas Epley著　"Mindwise" を読み始めました。副題は "Why We Misunderstand What Others Think Believe, Feel, and Want" となっています。

Despite what you've been told, beauty is not really in the eye of the beholder. People around the world, and even one-day-old infants, generally agree about who is hot and who is not. One of the primary determinants of attractiveness is a signal that has proven useful over millennia for finding healthy and fit partners to have babies with. Do you know what it is? Big muscles? Big smiles? Big breasts? Yes, for some, but there's one that's far more consistent around the globe: bilateral symmetry. That is, the degree to which the left and right sides of your body are identical.

"bilateral symmetry" の意味はその後に説明があるので「左右対称」の事だと分かります。
一応辞書の説明も見ます。
・Oxford English Dictionary: The property of being divisible into symmetrical halves on either side of a unique plane.: With few exceptions, animal color patterns show a high degree of bilateral symmetry in shape of pattern elements.
・Collins English Dictionary: the property of an organism or part of an organism such that, if cut in only one plane, the two cut halves are mirror images of each other: Rorschach gave them each bilateral symmetry, reflecting the symmetry of the animal body.

"bilateral symmetry" が美の一つの要因なのは認めますが、左右非対称でも美を感じるのも確かです。美人でも横や斜めから見れば左右対称ではないし、庭園でもフランス式の左右対称の幾何学模様も綺麗ですが、より自然な英国式庭園の方が私は魅力を感じるし、日本庭園も左右対称とは縁がありません。何が美を感じさせるのかは不思議です。