Goose pimples are tiny bumps or raised areas of a person’s skin that form just at the base of hair follicles. These raised areas of the skin are also seen in other animals, such as mammals and birds, and typically serve a number of different biological functions. Animals that are covered in fur or feathers are able to shift the positioning of the hairs or feathers by forming these tiny bumps, which can then provide greater warmth for the animal. Goose pimples also help an animal appear larger and more intimidating by shifting fur or feathers, though for humans these bumps are largely vestigial and provide little or no real benefit.
Also called goose bumps, goose flesh, and cutis anserina, goose pimples can form on just about any part of a person’s body with hair, though not on the face. They are created through a physiological reflex as tiny muscles, called arrectores pilorum, contract and pull the base of the follicle slightly to make the hair stand erect. The reflex that creates goose pimples is called horripilation or the pilomotor reflex and is typically controlled by the sympathetic nervous system, which is also responsible for a great deal of the biological “flight-or-fight” response system.
Goose pimples have also been found to form on other mammals, such as various primates, sea otters, and mice, as well as various species of fowl in which the contraction controls feathers rather than hair follicles. The name “goose pimples” comes from the resemblance of the raised skin to the appearance of goose skin when the feathers have been removed. In languages such as German, Italian, and Polish, the names for this reflex are similarly tied to geese, though in Spanish, French, and some other languages the term for goose bumps refers to hens rather than geese.
There are two basic causes for goose pimples manifesting on a person’s skin: strong emotional reactions and cold temperatures. Both causes of goose bumps are likely vestigial remains from prior states of human existence in which people were covered with greater amounts of hair. Extreme emotional conditions that may cause a response similar to “flight-or-fight” could trigger the pilomotor reflex in order to make a person appear larger or more intimidating to a predator or other threat.
Cold conditions can cause the response since creatures covered with fur can use the hair “standing on end” to increase warmth. Goose pimples cause hair to rise slightly, creating a layer of air between the fur and the skin that can act as insulation. While this is no longer effective for people with far less hair than primates and other mammals, the reflex remains in place.