Here's a breakdown:
Humans:
* Infants: Babies use facial expressions to communicate their needs and emotions long before they can speak.
* Children: As children grow, they learn to use facial expressions more consciously and intentionally.
* Adults: Adults use facial expressions to convey a wide range of emotions, from happiness and sadness to anger and surprise.
Animals:
* Primates: Chimpanzees, gorillas, and other primates use facial expressions similar to humans to communicate emotions like fear, anger, and happiness.
* Dogs: Dogs use facial expressions to signal their mood and intentions. For example, a wagging tail and a relaxed face typically indicate happiness, while a raised lip and bared teeth can indicate aggression.
* Other animals: Many other animals, including cats, horses, and even birds, use facial expressions to communicate with each other and with humans.
It's important to note that:
* While facial expressions are often instinctive, they can also be learned and influenced by culture.
* The meaning of specific facial expressions can vary slightly across cultures.
Overall, facial expressions are a powerful tool for communication that allows us to connect with others and understand their emotions.