The ability to voluntarily wiggle or twitch the outer ear, known as the pinna, is a distinctive human trait. This skill involves specific muscles surrounding the ear, remnants of a system that was far more active in our evolutionary past. While most people possess these muscles, the capacity to consciously control them has largely diminished. This makes the visible movement of the ears a relatively uncommon ability, requiring an examination of its prevalence and the underlying anatomy.
The Actual Rarity of Ear Movement
Voluntary ear movement is a skill possessed by a small fraction of the human population, confirming its status as a rare ability. Estimates suggest that between 10% and 22% of people have some degree of voluntary control over their ear muscles. However, this range includes individuals with very subtle control, and the number of people who can perform a full, noticeable wiggle of one or both ears is likely much smaller. True voluntary control involves the conscious activation of the muscles to produce a visible effect, often requiring significant concentration.
Many people exhibit slight, unconscious muscle activity around the ear, especially during intense listening, which is not the same as intentional movement. This subtle, involuntary reflex suggests that the neural pathways for ear movement are still present, even in those who cannot consciously manipulate their pinna.
The Muscles and Nerves That Control Ear Movement
The capacity for ear wiggling is governed by a group of three paired extrinsic auricular muscles, which connect the auricle to the skull and scalp. These muscles are the Auricularis anterior, the Auricularis superior, and the Auricularis posterior. The anterior muscle pulls the ear forward, the superior muscle lifts the ear upwards, and the posterior muscle draws the ear backward.
All three of these auricular muscles are controlled by the facial nerve, which is Cranial Nerve VII. Branches of the facial nerve, such as the temporal and posterior auricular divisions, innervate these muscles, transmitting signals from the brain to initiate movement. In most people, these muscles are underdeveloped, or vestigial, meaning they are present but functionally reduced compared to other mammals.
The ability to move the ears voluntarily often stems from a stronger connection between the facial nerve and these specific muscles. While some individuals are born with this innate control, limited movement can sometimes be achieved through targeted training involving neuromuscular feedback. Research shows that the superior auricular muscle is frequently the most active, even firing up in people who cannot consciously move their ears when they are struggling to hear.
Evolutionary Origins of the Auricular Muscles
The existence of these muscles in humans is a compelling example of a vestigial structure, a feature retained through evolution that has lost its original function. In many other mammals, such as cats, dogs, and horses, the auricular muscles are highly developed and permit extensive ear movement.
These animals use their mobile pinnae to locate sounds with precision, swiveling their ears to orient toward an auditory stimulus. For our ancient ancestors, this ability to direct the pinna was an important survival mechanism for localizing threats and prey.
The loss of this necessity in humans is linked to the development of other sophisticated sensory systems. As humans evolved greater neck mobility and relied more heavily on binocular vision and binaural auditory processing to localize sound, the pressure to maintain functional ear muscles diminished.
This evolutionary shift led to the reduction of the auricular muscles over millions of years, beginning about 25 million years ago. Although the muscles remain and the neural circuitry for movement persists, the ability to control them consciously has largely been deactivated or “fossilized” in the human brain. The muscles that control ear wiggling are biological relics, linking modern humans back to a time when swiveling ears were necessary for survival.