Of newborn people and puppies: autonomy of muscle control of emotional signals, eg smile/tail wag

I think I remember reading somewhere that human smiles are a sort of instinct. Ie, a complex series of muscle movements that signal (even in the absence of a reader of the signal) an emotion. Clearly different parts of the brain are working things out.

A) Is that true? Clever writers of fiction show a robot revealing his robothood by painfully “learning” how to smile, frown, etc. Infants clearly have to learn/figure out how to use their arms to point, but I know they don’t have to learn how to clench a fist or suck, what with having to hold on to mama’s fur and feed and all.

B) I’ve never bred puppies. Do they “wag” their tails spastically at first and then settle down to using their tails “correctly” only later?

In general, I’m trying to wrap my head around the autonomic brain functions in regard to higher-order (or is it?) signaling. In advance, turning blue from lack of oxygen is a “signal” to others in a society consequent to autonomous nervous system function, but that’s a different issue.

Moderator Note

Corrected spelling in thread title (mile -> smile)

Entirely anecdotal: I have an adult dog who knows how to wag her tail, can do so, but does not choose to in most contexts.

She’s rescued, found on the street at six months of age, and I believe from her general ignorance of dog body language that she was raised in isolation. She didn’t know anything about play stance, tail signals, or anything really when we brought her home; she’d just stare blankly at other dogs.

She has learned to wag her tail – specifically when greeting other dogs – and will wag three or four swings, as if to say “I come in peace.” Then she stops, and does NOT wag when playing. Nor does she wag when greeting her humans, eating, getting a new toy, or at any time that she seems to be happy or content – she ONLY uses it briefly when meeting a strange dog.

Just watching her, I am inclined to think tail-wagging is a learned communication; if it’s instinctive it doesn’t seem to be an instinct she has.

Babies smile when they are happy. They don’t smile when they are angry.
It starts at a very early age but premature babies don’t smile, or they just aren’t that happy.

I fondly remember the dog I had when I was young. I often tell people how I would hold one sort of food in my right hand, another in my left hand, and offer both to the dog. Then I’d watch him look at one, then then other, back and forth, trying to decide which one to take. I use this story to demonstrate why I believe that dogs are capable of thinking and choosing, on some level.

In that light, I find Sailboat’s story fascinating. I had never thought of tail-wagging as a learned behavior, but perhaps I was wrong.

A newborn baby will instinctively mimic simple aspects of an adult’s facial expressions, such as sticking out the tongue or widening the eyes. It may take a few weeks before they have enough coordination of their facial muscles to manage a clear smile. Link