Let's clear up some misconceptions.
1. It's a combination of genetics and environment. Try living in Africa, where people are starving, don't have access to good medical care, are surrounded by germ-carrying bugs and parasites, can't go to school, etc. and try to get a good IQ score. I can guarantee you that this environment is depressing their average score by a significant amount. However, there are also differences in brain size between races and we know that brain size correlates with IQ, so the mean IQ differences should be partially caused by genetics too.
2. Some of these figures are probably inaccurate. I believe most of them are collected by Richard Lynn, who based his research on some good studies and some bad ones but treated them as if all the studies were equally good. For example, some of the countries did IQ studies with a very low sample size, or took samples from groups of people who are not representative of the country's overall population.
3. More IQ doesn't necessarily mean more development. The amount of development in a country can be influenced by other factors, like contact with other countries to trade and share ideas, the type of social organization in a country, the personalities of the people (there might be smart people who don't like to invent things, or their might be less smart people who love to invest all their time to come up with new ideas), the environment of a country, and so on. IQ definitely has an influence, but it's not the only thing that counts. That's why we can't assume a country has a high or low average IQ based on its level of development.
4. These charts show the average IQ of each country, but not the standard deviation. This also varies between countries. For example, countries in the Balkans tend to have a lower average compared to Western Europeans, but also tend to have a higher standard deviation.