Symmetry creates balance, and balance in design creates harmony, order, and aesthetically pleasing results. It is found everywhere in nature, and is probably why we find it to be so beautiful.

Animals are primarily classified according to morphological and developmental characteristics, such as a body plan. One of the most prominent features of the body plan of true animals is that they are morphologically symmetrical. This means that their distribution of body parts is balanced along an axis.

In addition to having a more developed nervous system, bilaterally symmetrical animals can move more quickly than animals with other body plans. This bilaterally symmetrical body plan may have evolved to help animals better find food or escape predators.

Radial symmetry may provide some advantages, but it seems to come with a number of disadvantages, too. A radially-symmetrical animal has no front and no back, no right and no left; such animals typically have their sense organs scattered around the body surface instead of concentrated in one region.

Radially symmetrical organisms have no right and no left and no front and back, such organisms have their sense organs distributed around the whole body surface instead of concentrating in one particular region. This gives them the ability to sense danger from their prey from any direction.

One advantage of having radial symmetry is that the animal can get food from any direction. Larger, more complex animals all have bilateral symmetry. They have very different front and back ends. Different parts of the body are specialized to do different jobs.

For sessile (sedentary) organisms, radial symmetry is useful because the animal can just “sit down” and grab food or detect threats from all directions.

Radial symmetry equips these sea creatures (which may be sedentary or only capable of slow movement or floating) to experience the environment equally from all directions.

Radial symmetry is especially suitable for sessile animals such as the sea anemone, floating animals such as jellyfish, and slow moving organisms such as starfish; whereas bilateral symmetry favours locomotion by generating a streamlined body. Many flowers are also radially symmetric, or ‘actinomorphic’.

: the condition of having similar parts regularly arranged around a central axis.

Chronic stress-induced elevation in cortisol may alter its own negative regulation with multiple long-term consequences for physical and psychological health. One of the most reliable physical traits associated with mental, apparent physical health, and competitiveness is the degree of facial fluctuating asymmetry.