Selfishness (Read: Kids are jerks) [But it's not their fault]

Alright, I promised controversial, so I suppose I have to give it.

Harkening back to a topic idea suggested by a dear friend however many months ago, I'd like to discuss children and their propensity to be assholes.

Now, this immediately gets into tricky territory since we haven't adequately defined what a jerk is or what it is that makes someone a jerk.
Nor do I actually intend to define it; largely because any definition I use would be meaningless (I attribute this to a lack of skill in wordplay on my part rather than philosophical possibility).

Kids are and are not jerks. And that's the short and skinny of a very complicated question regarding human nature.
Firstly, we're examining two separate things, and I should go right ahead and differentiate them;

Intention

Behavior (consequences)

In this case, the intent of behavior is most usually totally unrelated to the consequences or outcome; not because kids don't care, but because they haven't developed a sufficient understanding of empathy to this point to be able to shift perspectives easily.

The behavior, on the other hand, is that which produces measurable effects; the consequences of a child's actions regardless of his/her intent with those actions.

Adults are far better at pairing appropriate intentions with appropriate actions than kids, but even we mess it up with a fair amount of frequency. See back-handed compliments, jokes that cross the line, accidentally hurting your friends, etc.

Rarely do our bad intentions lead to good outcomes, but often do our good intentions go awry. Hence the old adage, "The road to hell is paved with good intentions."
This is partially because our actions are based off of assumptions that we have, which are in turn based on prior knowledge of cause and effect. We assume that in order to create outcome A, we must perform action B, since something similar has worked for us in the past.
Problem is, humans are all unique, and their problems are individualized too. As a result, we can't just go around generalizing solutions for everyone; Doesn't work very well.
This results in a rather frequent phenomenon in which we misinterpret what actions will yield what consequences given our intentions.

"I want my significant other to be happy, so I'll be them flowers. Flowers made my last SO happy!"
"I'm allergic to roses! I told you that!"

Turbo cliche example, but it fits.

Now kids? They're missing a step in this process. They don't have much prior experience, and what little they have is constantly building off of new experiences. As a result, there's a lot more that goes into the "assumption" part of the transaction, and a lot less thought that goes into the "intention" part.

"I like it when I make people laugh. Throwing sand at this person makes people laugh."

The assumption here is limited to an inherently selfish tendency- the tendency to do what makes you happy in order to elicit positive feelings. There's little to no consideration for the "victim" in events that involve children because there is virtually no prior experience in the field of empathy. There is no cost-benefit analysis being performed; it's more like a scientific experiment to attempt to recreate circumstances and data in an incredibly rudimentary sense.
Kids are rarely malicious, they're just more curious than they are aware of the people around them. All people and all things are a means to an end because children have not developed the sense of pleasure derived from making others happy in nearly the same capacity as adults (sometimes) do. Which, yes, ultimately means that there's some sense of selfishness within our empathy and our desire to help others. It makes us feel good. We derive a satisfying sense of accomplishment knowing that our actions have potentially lifted up another. Sometimes, we feed into this so much that it becomes our very reason for living.
Sometimes, on the other hand, we never develop this sense at all. Some people have a strict lack of empathy that carries with them for their entire lives.
Others have the sense of empathy crushed and pushed out from them by a world and a culture that encourages psychopathy and cruelty.

Kids do not act because they lack the empathy, they act because their empathy has not been nourished yet. This is why it's so important for good role models to deliberately make it a point to remind children that every human is valuable to their own end, and that each desire we have is matched by an equivalent desire in each other person; an infinitely complicated and interconnected web of similarities and equivalencies can be drawn through every human being on the planet. It is a difficult perspective to swallow, and not one that we can wrap our minds around without assistance for a long time- especially for kids.

So kids are assholes, but it's not their fault.
Not to say that excuses their behavior. ;D