Moving from country to country at a younger age has a prominent effect on a person, because of how they are exposed to more than one culture while they are still developing. Different cultures have different expectations, so the child can take the knowledge they obtain from one culture and apply it to the other. Education opportunities are also different. Depending on the area, different resources are offered, and naturally, with more of these resources and more opportunities, the child is able to fulfill more of their potential. Some are also exposed to a completely new language at a young age, allowing them to become fluent in more than one language, and think differently than someone who is only fluent in one.
In a nature-nurture debate, this result proves that the person is affected by the environment they grow up in, and it is not a result of the individual themselves, but more so the factors around them, and in specific the culture around them during their childhood. Intelligence studies depend less on the individual potential of a person, and more on what kind of opportunities the person had.