Patterns in Nature: Symmetry ￼
Bilateral animals, including humans, are more or less symmetric with respect to the sagittal plane which divides the body into left and right halves. Plants and sessile (attached) animals such as sea anemones often have radial or rotational symmetry. Fivefold symmetry is found in the echinoderms, the group that includes starfish, sea urchins, and sea lilies. People observe the symmetrical nature, often including asymmetrical balance, of social interactions in a variety of contexts. These include assessments of reciprocity, empathy, apology, dialog, respect, justice, and revenge.