However, even if that is true, it still may be the case that some small amount of bias does indeed exist in IQ tests. For example, I was given an anecdote about a Chinese boy, who, when shown a picture of people using umbrellas on a dry day and asked what was wrong, responded that nothing was wrong with the picture. Apparently he interpreted the umbrellas as parasols, something Americans would be less likely to do.

Regarding intelligence of agriculture vs. hunting, I would argue that hunting may require more skill, but in agriculture, intelligence (and creativity) has a greater reward (than in hunting). That is, it is very difficult to automate tasks in hunting (beyond things like inventing guns, which they obviously hadn't done), but agriculture has been steadily getting more efficient with creative inventions from iron tools to plows to the cotton gin and so on. Hunters today still use very similar methods to ancient times. For that reason, I believe that an agricultural society selects more strongly for creative thinking, while a hunting society selects for physical skill and quick thinking. The creativity required to change society in order to accommodate more crowded conditions also undoubtedly requires intelligence. Anyways, enough of that...

I do agree with you that there is likely a small amount of bias in tests like these, and your example is a good one. Another I have heard was about a question which involved the "knowledge" that lemons are yellow. In Latin America, however, lemons are more often green, obviously giving Latin Americans a disadvantage on that particular test question.