[madisgram]

the findings are that mankind's basic generosity is not based on a selfish act expecting something in return. i'm not surprised by the findings because i feel mankind is in the purest sense is giving. it's when this natural tendancy gets "lost" by select groups with agendas that are self serving that things go awry.
^^^^^^^^
ScienceDaily (Aug. 1, 2011) — Imagine you're dining at a restaurant in a city you're visiting for the first -- and, most likely the last -- time. Chances are slim to none that you'll ever see your server again, so if you wanted to shave a few dollars off your tab by not leaving a tip, you could do so. And yet, if you're like most people, you will leave the tip anyway, and not give it another thought.
These commonplace acts of generosity -- where no future return is likely -- have long posed a scientific puzzle to evolutionary biologists and economists. In acting generously, the donor incurs a cost to benefit someone else. But choosing to incur a cost with no prospect of a compensating benefit is seen as maladaptive by biologists and irrational by economists.
http://www.sciencedaily.com/releases...0725162523.htm

[Sunna]

While I believe that empathy and, with it often, generosity are natural to a human being, I think the tip example is not a good enough illustration of it.

There are 2 elements here that explain the phenomenon more than amply without adding inborn generosity.
1) social conditioning
2) self-judgment

I have seen this in action with my mother, who is not an ungenerous person, but she's never been conditioned to think that not leaving a tip is rude, greedy, or a form of cheating the waiter/waitress out of their payment (i.e. something that later may make her feel bad about herself). Where she comes from waiters are not tipped, tipping is/was a foreign custom taken upon by snobs who wanted to immitate foreign ways and furthermore impress their class superiority over the person being tipped. When I explained to her that it was part of waiters wages, she thought it was kinda silly, but she considered it and decided she doesn't want to tip. The waitress, in her view, did not perform any extraordinary services, wasn't extraordinarily pleasant or attentive. Furthermore my mom, decided that that she is actually much poorer than the waitress and need that $4 more. (Don't be aghast *I* left a tip).