This back and forth sounds a great deal like "NO U" being shouted on 4chan.

Are there any sources, papers or studies indicating whether it is learned, innate or both?

Sources and empiricism are what we should be resorting to, not down-votes.

You're not going to find a lot of people jumping through that hoop, given that 5 seconds with Google is all that it takes. This isn't some controversial developmental theory, and this isn't a formal debate.

I am not taking sides. I may even have done some reading up already, but I want to remain neutral.

I want to know why the people going back and forth think one way or the other. If I rely on my own research I might not get the nuance that a psychologist or other person with a vested interest would be able to share.

There seems a great deal smoke but no light in this discussion. This is uncommon here on hacker news, normally sources are appreciated and I frequently see them brought in well before an argument begins, even on extremely casual topics. They often earn an few upvotes too.

Then shed some light on it, don't spend a handful of posts complaining about it while cryptically suggesting the value of your own neutrality and what you might or might not know. Again, this isn't a controversial topic, and just a case of one poster who didn't seem to know about the topic in general, as indicated by believing that one aspect of the Macdonald triad being diagnostic for a child.

So again, if you want to add to the discussion, add to it, don't try to control it.

As a general rule, in scientific circles anyway, the person making an assertion is the one who gets to support it. Asking "Why do you believe that?" is always valid.

[citation needed], people generally need to pass a crank test or be ignored as not worth the effort of speaking to.

In this context someone explaining themselves would be nice, even without citations (they would be nice though). Instead I was getting downvotes for asking "why" just with a few more words.

At the moment there is no reason to believe either side and plenty of reasons to dismiss both, not as cranks, but at least as cranky.

/I assume the thread is dead so..

Complaining on a form inherently lowers it's quality. As a rule Down-vote, Flag, or say nothing don't clutter up HN with posts that make for poor reading.

And yes, mass downvoting both sides of a thread is often better than getting in the middle of a heated debate.

Given that this is your response, and you've chosen not to shed some light on the subject yourself, the options left to describe your motives are not positive.

That question was asked, and answered by several people. "Why do you think that?" and "You haven't cited to my satisfaction, although I've done my research... which I'm not sharing for... reasons..." isn't the same thing at all.

Lets not pretend that it is.

A down-vote instead of a link, I don't know what I expected.

It's a complex emotion, and we don't have good tests to measure any but the most basic emotions in infants. But we do have good indicators that 12 month old babies show empathy.

As well as dogs. Dogs have empathy, even for humans.

So yeah, the idea that an 18 year old is struggling with an emotion that babies and dogs don't have much trouble with is a silly proclamation IMO.