This video, we're going to briefly discuss age structure and how it can affect the country's human population growth. Age structure is really just the number of living individuals in a population at each age group, and it is often displayed as an age structure pyramid like the ones you can see down below, where each level of the age structure pyramid corresponds with a very specific age group. These age structure pyramids are color coded so that males appear in a blue color and females appear in a pink color. The size of each of these blue and pink bars tells us the percentage of the population that each of these groups makes up of the whole. It turns out that the age structure alone can actually reveal a pretty decent amount of information about the development and the industrialization of a country.
Developing non-industrialized nations, such as Zambia, for example, a country in Africa, tend to have these really bottom-heavy age structure pyramids where they have quite a lot of really young individuals and relatively few older and middle-aged individuals. These developing non-industrialized nations tend to have really high birth rates and high death rates as well, which creates high mortality rates and low survivorship from age group to age group in the age structure pyramid, and this leads to relatively low life expectancy. On the other hand, already developed and industrialized nations, such as the USA, tend to have more balanced age structure pyramids, and they tend to have relatively low birth rates and low death rates, which creates relatively low mortality and high survivorship from age group to age group, and this leads to relatively high life expectancy. The transition from a developing non-industrialized nation to a developed industrialized nation is referred to as demographic transition. Demographic transition is really just this shift from having really high birth rates and death rates to having really low birth rates and death rates as the country industrializes.
Notice that this purple arrow down below is representing demographic transition. Again, this shift from developing and industrialized nations to a developed industrialized nation. This here concludes our brief lesson, and we'll be able to apply these concepts and problems moving forward, so I'll see you in our next video.