Would the child instinctively learn to smile?

[Lunatic Higher]

[FONT=&quot]This is about human facial expressions and how they contribute in an evolutionary way that's beneficial to a human.When a person is surprised, their eyes tend to widen, and their eyebrows tend to lift. In doing so, more light is able to strike the retina in the eye, so that the person is more capable of seeing around them, and making a plan if necessary. In giving a look of disgust, the upper lip of the person seems to curl to the side slightly, the nose scrunches and wrinkles. This could be useful for stopping the nose from inhaling a dangerous odor, such as poison, and the lip curling makes it simpler to spit something out, possibly a poisonous food. My question is, what is the benefit of a smile? I guess my question is more directed toward people who believe in human evolution, but everyone can participate if they choose. Say that a baby was left in the wilderness; maybe raised by animals. Do you think the child would instinctively react to the feeling of contentness by smiling, or do you think society has morphed people into that? It's obvious that we don't need these reactions for evolutionary purposes anymore since we don't live in the wilderness and we're aware of consequences like poison and such, yet we make a very wide eyed expression when we're surprised. Humans are very animated. How much of a role do you think society plays in our facial expressions?
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