Instinct measures dynamics unconsciously.
All things on our planet are bound by dynamics. Natural objects are subjected not only to gravity but also too many other kinds of forces arising from their surrounds, such as wind, load, and surface tension. Instinctively seeking to minimize the impact of these forces, nature tends to seek out optimal structures. Forms emerge naturally in the course of resisting these dynamic influences using the minimum materials necessary.
Have you ever wondered why insects have thin legs while those of an elephant are so thick? The answer can be explained in simple terms as follows: as distance doubles, volume grows by a factor of 8; gravity operates in proportion to volume, so it also increases cubically in proportion to distance. This means that it is necessary to alter the thickness of the legs that support the creature's load. The fact that large creatures move more slowly is also because they are subject to a stronger force of gravity. Not only animals but also plants, geological formations, and all other natural forms are deeply interconnected with dynamics. It seems that dynamics are also closely related to the aesthetic sense of humans.
We see beauty in forms that are created naturally in the course of resisting dynamic forces, such as objects floating in space free from gravity, structures built with ample detail, and taut curves subject to tensile force. Surely this is because we unconsciously perceive the strong forces flowing within such forms. In beauty, the ultimate goal is not to create form, but to exhibit the most straightforward type of form in opposition to the surrounding dynamics and flows.
A simple string cut into equal lengths and allowed to hang down. Why do we see beauty in this form? One of the line forms that is most pleasing to humans is the catenary curve. This curve is created naturally when you let a string held at both ends go slack. Shaped by resistance to the force of gravity, this line is an ideal arch form in structural terms. It is well-known that Antonio Gaudi designed the overall structure of the Sagrada Familia church by creating catenary curves using weighted strings, then flipping those curves vertically. The fact that humans sense beauty in such lines may well be due to the operation of our instinct for dynamics, whereby we perceive tension within forms.