“Humans use more energy to frown than to smile.”

The popular adage that it takes more muscles to frown than to smile is a widely circulated piece of wisdom, often used to encourage a more cheerful disposition. This notion has been part of our cultural landscape for a long time, with its exact origins largely unknown, having been passed down through generations as a simple truth. The specific numbers of muscles cited for each expression vary wildly in different tellings, ranging from around 10 to 22 muscles for a smile and 33 to 65 or more for a frown, which itself is a strong indicator of its mythical nature.

Scientifically, pinpointing an exact number of muscles for either a smile or a frown is challenging, if not impossible, due to the complex and interconnected nature of human facial muscles. Different types and intensities of smiles and frowns engage varying combinations of muscles, and individual facial anatomy can even differ slightly. While some sources suggest frowning might engage more muscles for certain expressions, others contend that a basic smile or frown can involve a similar, small number of muscles. More importantly, the energy expenditure for either expression is negligible. The amount of effort generally relates to the severity of the expression, rather than the expression itself, and forcing any expression can feel like more work.

People readily embrace this myth because it carries a positive and encouraging message: it implies that being happy and approachable is easier and less taxing than being dour. The idea that smiling conserves energy and is a simple choice to improve one's mood resonates deeply. This appealing sentiment aligns with the desire to promote positivity and friendliness, suggesting a straightforward path to personal well-being and better social interactions.