NACA Animal Control Officers Practice Test

The expression of happiness typically involves the activation of certain facial muscles that create a specific appearance, which often includes the presence of crow's feet eye wrinkles. When a person is genuinely happy, they tend to smile, which not only affects the mouth area but also causes the skin around the eyes to crinkle, resulting in what are commonly known as "crow's feet." This phenomenon occurs because the muscles around the eyes, specifically the orbicularis oculi, contract during genuine smiles, reflecting authentic emotion.

Other options describe facial expressions that are associated with negative emotions or do not represent happiness. For example, furrowed eyebrows, narrowing of the lips, and downturned lip corners are more indicative of confusion, anger, sadness, or discontent. Thus, the presence of crow's feet eye wrinkles is a reliable indicator of a joyful expression, distinguishing it from more negative emotional states.