in the chooseTab function you have the following line:
html += "<img src='/static/level3/cloud" + num + ".jpg' />";
the src opens with a single quote and looks for the 'num' var. So instead of num in the URL, you close the single quote and then close the image tag, and then run your script.
Just to provide some counter-points and discussion:
(a) Not everyone in the US is religious; and of those that are, not all religious people think of sharing in the same way. I think it would be difficult to say religion in the US is what causes people to split more equitably. Also we do not know the beliefs of the foreign populations in the article.
(b) In both cases it was a meaningful amount of money. The article stated it was worth a few days pay in one of the countries, $100 is about 2 days pay at minimum wage in the US.
(c)I think your point here speaks to the psyche of American's that the author writes about. It would be interesting to perform the game within "only poor" sample groups and "only wealthy" sample groups inside the US.
Unfortunately you don't buy an always open 15 Mbps pipe, you buy "15 Mbps peak speeds", or at least that's how it is worded for me. Which means at peak usage times you expect to get lower than 15 Mbps.