Why an audience can speed up a practiced action
Being watched can raise alertness: attention narrows, the body becomes more ready to act, and responses may come out with greater force. Psychologists call this social facilitation—the tendency for other people’s presence to affect performance.
The key is what the task asks of you. If you have practiced a movement until it feels almost automatic, heightened readiness can help that well-established response arrive faster. A familiar pianist may strike a practiced passage with more energy; someone who knows a routine may perform its steps more briskly. The audience supplies no extra knowledge or technique. It changes the conditions under which existing skill is expressed.
Why the same pressure can hurt
A difficult or unfamiliar task depends on choosing among possibilities, holding instructions in mind, and correcting mistakes. Those steps require careful attention. When arousal rises, attention can become less flexible, and the first or most habitual response may crowd out a newer, less secure one. That can make a complex task harder even as a simple, well-rehearsed action gets quicker.
This is why “perform better under pressure” is not a general rule. The effect depends on whether the response most readily brought to mind is also the one the task requires. Practice matters because it makes the useful response more dependable; watching eyes mainly amplify the conditions already in play.
The practical consequence
Rehearsing under conditions that resemble performance can make the audience feel less novel and help a skill become reliable. But adding pressure cannot substitute for learning the task. An audience can turn up the volume on a practiced response—not make an unpracticed one appear.
