If we're going to look at this realistically we must acknowledge that all things are one, instinct no more separated from emotion than my tea kettle from a rainstorm that may happen later this spring.
All individuals, including infants lacking any learned behavior do not lack emotions, evoked by the same stimuli as developed individuals. Example. Here is a scared human that obviously has no preconceived notion of what to do with facial muscles when scared:
And here is a human that does know how to act scared, doing so:
That's enough to convince me that there's at least some hardwiring upstairs.
The article that Eclogite linked to states that instinct and emotions are not the same, but closeley related (not unlike my tea kettle).
There are reasons for all of our instinctive reactions, and while the article only mentions a few, I think it's safe to presume that the others are simply still illuding us.
Quote:
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the blood vessels in anger, the secretion of tears in grief, the laughter in response to wit and humour, have been held to assist in relieving the abnormal circulatory conditions in the brain
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whew.

(So sorry Eclogite)