This is the audio file for the ppt presentation on diffusion.
The first slide provides you with a definition of diffusion…when we talk about diffusion in terms of human geography we are looking specifically at cultural diffusion. There are really two variables at work…the spread of something across space and time. Cultural diffusion may be the movement of an idea, technology (computer), a custom or practice of a group of people, the spread of a product, other cultural traits such as clothing or certain types of diseases.
There are two main types of diffusion: expansion and relocation. Expansion diffusion is further broken up into three sub groups: contagious, hierarchical and stimulus. Think about the words expansion and relocation as we go into greater detail in the next slides.
The first type of diffusion we’ll look at is expansion diffusion. This is where you have an innovation or an idea, a fashion trend, that develops in a source (hearth) that remains strong at the source and spreads outward. Two points: the idea or innovation will remain at the source or hearth as well as catch on where it spreads; also, the number of people that use the invention or idea will increase. As the innovation or technology spreads the number of users or believers will increase.
Moving on to the three types of expansion diffusion. Hierarchical diffusion pertains to a disease, innovation or technology that spreads to a vunerable segment of a population. An easy way to look at this…expansion diffusion implies that the number of users will remain stable at the source but also expand as the idea or disease moves. So a greater population uses the innovation in the end. Urban areas vs rural areas, which of these would be more likely to adopt a certain type of music, or even adopt a fashion trend before the other, in general because large urban areas offer larger amounts of people and more diverse types of people they are more likely to adopt different fashion trends especially radical ones we see and it will happen more quickly in urban areas vs rural areas
This graph shows the US AIDS deaths comparing data from males and females. A good example of hierarchical diffusion in a couple of different ways…first, in terms of a hierarchy males will be more likely than females to contract AIDS as well as die from AIDS. Second, the incidence of AIDS will be higher in urban then rural areas. This is because the population is larger and more diverse and this leads to greater acceptance of a different lifestyle, one often associated with or leading to the contraction of HIV/AIDS.
This slide shows AIDS cases worldwide. Note isolated pockets of HIV cases as of 2010. Note the two African countries and Asian countries standing out; they are unconnected to each other and relatively isolated and this demonstrates a hierarchy of sorts. Note that both India and China have populations well over one billion and ethiopia and Nigeria are the most populated countries in Africa, giving them the large populations required.
This slide links you to a demonstration of the spread of the 1918 Spanish Influenza epidemic in the US. Click on the map and a web window will open; watch for the urban areas and other regions hit first before the US becomes saturated with the disease.
This next form of diffusion is a form of expansion diffusion called contagious. Remember that with expansion diffusion the idea or innovation spreads outward from the source but also remains strong at the source, and the number of users of an innovation or believers in an idea will increase. With contagious diffusion, nearly all people that come into contact with a disease or innovation will adopt it. The original map of the black death showed those isolated areas and we said it demonstrated hierarchical diffusion; often what begins as hierarchical diffusion eventually becomes contagious diffusion. Take a look at your Kuby book pages 66 and 67 for additional information.
This next map shows the spread or diffusion of Islam, which is an excellent example of contagions diffusion. You can view the source in central Saudi Arabia and the spread over time throughout the middle east and north africa. By the end of the 1200’s virtually all of Southwest Asia was saturated with Islam.
This map shows a different perspective of the Black Death in Europe as of 1349. If you take a close look you will note the Mediterranean, Black and Caspian Seas, but notice the coastal areas become saturated by this time, again showing contagious diffusion. There are a couple of pockets between Spain and France, north by the Netherlands and Venice that remain isolated from the black death. A contrast to the example of the Black Death in Asia of which it was hierarchical diffusion rather than the contagious diffusion of Europe.
The next form of expansion diffusion is stimulus. Remember the number of people using an innovation still growing and the use of an innovation still remaining strong at the source. Stimulus diffusion involves an idea stimulating experimentation and adaptation of the original….good way to think about this is to think about a plow, farmers in Europe may have used an iron plow hooked up to a horse or cattle…say someone visits Europe from Africa…Africa has no horses or cattle but notices how Europeans use the plow and the animals to cultivate their fields. This person returns to Africa and adapts the innovation of the iron plow hooked to a draft animal into a wooden instrument that is able to be attached to a camel or other available animal…experimentation changed the original form but the adaptation resembled the original
The second type of diffusion is relocation diffusion…a couple of noticible differences. Relocation diffusion allows for the spread of an idea or innovation through the movement of people from one place to another; also, the number of users will stay the same because the innovation moves away from the source along with the people One example of this that I like to use…do you use the word casserole or hot dish? From my understanding the word casserole was actually brought to us by the French, for whom it referred to an actual baking dish, and not the entrée itself. People in Wisconsin use the word casserole more frequently and people in Minnesota use the word hotdish…hotdish is a Scandinavian word brought to Minnesota by the Nowegian, Swedish, and Finnish immigrants. Could this represent higher immigration of French into Wisconsin?
Diffusion Ms. Patten 2012
Definition Cultural Diffusion is a process by which a cultural characteristic spreads across space from one place to another over time. Idea, technology, custom, product, cultural traits, diseases
Types of Diffusion Expansion Relocation Contagious Hierarchical Stimulus
Expansion Diffusion An innovation or idea develops in a source area and remains strong there while also spreading outward Item remains at the hearth Number of users or practicers grows
Expansion: Hierarchical Spreads through certain vulnerable segments of a population Large urban areas vs rural areas
Expansion: Contagious nearly all adjacent individuals are affected
Expansion: Stimulus the idea stimulates experimentation and adaptation of the original animals for farming
Relocation Diffusion An innovation or idea is spread through physical movement of people from one place to another Number of users stays the same Idea moves with the people Casserole vs hot dish (Wisconsin/Minnesota)