The Country Similarity Index attempts to quantify how similar countries are to each other relative to other countries. The index is a statistically-based way to measure this. It weighs equally five major aspects of countries: their demographics, culture, politics, infrastructure, and geography. The methodology is exactly the same for each country.
The data from the Country Similarity Index was used to cluster countries into different regions. This resulted in 9 distinct macro-regions: Western World, Central & South America, Middle East & North Africa, Sub-Saharan Africa, Central Asia, South Asia, East Asia, Southeast Asia, and South Pacific. A map of the different regions can be found on this page.
However, it may best to look at countries as a connected web, not as hierarchical clusters, since the data reveals the relationship of countries to each other is more of a gradient than having clearly defined clusters. Therefore, a graphic was created to reveal more intricate linkages between countries rather than simply grouping them into regions.
Hopefully, this graphic will help people understand the similarity of countries relative to each other better than a traditional map, which only shows geographic adjacency. This shows other political, cultural, demographic, and technological adjacencies that a physical map of the world does not account for.
The logic of the connected web is as follows: each country is connected to its most similar country and also the next most similar country that is not more similar to the countries more similar to the country. For example, Brunei’s most similar country is Malaysia. However, its next most similar countries, Indonesia, Singapore, and the Philippines are all more similar to Malaysia than Brunei. The next country that is more similar to Brunei than Malaysia is Oman. Therefore, Brunei is on a spectrum somewhere between Malaysia and Oman.
In reality, the web would need to be three dimensional, since there are limits to what can be shown clearly on a two dimensional graphic. In order to fit all the connections on a two dimensional web, it was necessary to break some of the lines where there is significantly less similarity. For example, United States is on a spectrum between Mexico and Canada. However, since the United States is far different from Mexico, it only has an arrow, not a full connection. Furthermore, some connections are not shown on the map if the country already has two connections. For example, Croatia is disproportionately more similar to Italy than any other Slavic country. However, since Italy is between France and Spain while Croatia is between Slovenia and Serbia, this connection ends up not being shown.
Please keep in mind that just because some countries are close to each other on this graphic, does not necessarily mean they are very similar to each other. For country specific questions, it is best the consult each individual country’s page on this site. Only the lines connecting countries are meaningful, not their location on the graphic. For example, although Suriname and Vanuatu are next to each other in the graphic, no lines are between these countries, so no relationship is necessarily implied. The thicker the line, the closer the similarities between the countries are.
Region 1: The Western World
In the Western World, some clear groups emerge. The English-speaking countries create a spectrum with the United States and Ireland at the extremes. A loop forms approximately around the Baltic and North Seas. There is also a clear group of countries located around the Mediterranean Sea. Countries formerly part of Austria-Hungary are clustered together. Slavic countries are connected to each other, but the former countries of Yugoslavia are especially close together. Except for the Baltic states, countries of the former Soviet Union are also grouped together. In general, countries with the same religious denomination are linked too.
Spain and Chile are most similar European-South American pair of countries. Both countries speak Spanish and have a relatively high level of development. Kazakhstan is the most Russian influenced country in Central Asia. Many ethnic Russians still live there, even after the fall of the Soviet Union. Their infrastructures are still heavily integrated. They use the same power grid, dialing code, and railroad gauge.
Region 2: Central & South America
Three distinct clusters of highly similar countries form within this region: South America, Central America, and English-speaking countries. Interestingly enough, Mexico is one exception to this pattern. One reason is that Argentina and Mexico both have a lot of dry lands, but also some tropical areas. Furthermore, their GDPs per capita are nearly identical.
Haiti is the most similar in the region to a Sub-Saharan African country, since most of its people are of African decent, its development is not very high, and like many African countries, has French as its official language. Due to the history of British colonization and Indian indentured labors in the Caribbean, especially in Trinidad & Tobago as well as Guyana, both Mauritius and Sri Lanka are connected to these Caribbean countries, although they still have some big differences, especially in geography.
Region 3: Middle East & North Africa
The Levant is at the geographic center of the Middle East, so it is no wonder that there are three distinct branches coming off from Jordan. One branch includes Arabic-speaking countries in North Africa, while another branch includes the countries located on the Arabian Peninsula. A third branch includes the countries in the Middle East that are not Arab, but adopted the Arabic script although they speak Indo-European languages, like Iran, Afghanistan, and Pakistan.
Israel is a real outlier within the region. It has a different religion and also a different writing system than the countries around it. It also has more European traits than other countries in the Middle East and North Africa. Many Jewish Europeans have migrated to Israel in the past century. Yemen has some traits of both the Middle East and Sub-Saharan Africa. It is one of the poorest Arab countries, since its infrastructure has been destroyed, due to on-going civil war.
Region 4: Sub-Saharan Africa
In Sub-Saharan Africa, there are four distinct groups of countries: countries bordering the Sahara Desert that are heavily influenced by Arabs, English-speaking countries in West Africa, English-speaking countries in East and Southern Africa, and French-speaking countries.
Madagascar is one outlier in the region, since its people natively speak Austronesian languages and have some Southeast Asian ancestry, so it has some traits of countries in the South Pacific, unlike the rest of Sub-Saharan Africa. Vanuatu is especially similar to it since both countries are tropical islands that were once colonized by France. South Africa and Australia are the most similar pair of Sub-Saharan African and Western World countries. Both have English as their official language and are mostly Christian. They also enjoy cricket and rugby as well. Furthermore, their geography is similar. They are both located in the Southern Hemisphere and border the Indian Ocean. They have a variety of different climates, but are mostly desert. In comparison to other countries in Sub-Saharan Africa, South Africa is fairly well developed as well. Equatorial Guinea is the only country in Africa with Spanish as its official language, so Nicaragua is another tropical Spanish-speaking country that it connects to.
Region 5: South Asia
India is clearly at the center of the highly diverse South Asia region, with several countries that border it being similar to it in different ways. Bhutan is part of the South Asia region, but it has many of the same traits as countries in the Mainland Southeast Asia region, since it is mostly Buddhist and its people have mostly East Asia ancestry. At the other end of the spectrum, Pakistan is more like the Middle East. It is predominately Muslim, uses the Arabic script, and its land is mostly dry desert. Bangladesh also branches out from India, but it also has some traits like Indonesia since they are the two largest Muslim majority countries located in tropical climates.
Region 6: Central Asia
The core countries of Central Asia are made up of the former republics of the Soviet Union that are mostly Muslim, but now have secular governments. Turkey is the most like Europe. Not only is it geographically closer, but it is also part of NATO and the European power grid. Furthermore, its people are mostly Caucasian in ancestry. On the other end of the spectrum, Mongolia is the country in the region most like East Asia. It is mostly Buddhist and its people have mostly East Asian ancestry. Tajikistan is the only country part of Central Asia whose native people speak an Indo-European language. Since Dari and Tajik is nearly the same language, Afghanistan and Tajikistan are quite similar. Furthermore, both are extremely mountainous landlocked countries.
Region 7: East Asia
The countries of East Asia are relatively different from each other, but they are also far different than most other countries in the world, so they are grouped together. They have a clearly defined circular relationship located around the East China Sea. China and Taiwan are both Chinese. North Korea and South Korea are both Korean. However, China and North Korea both have authoritarian governments run by a single party. Taiwan, South Korea, and Japan have democratic governments and are highly developed.
Some Southeast Asian countries have many traits of East Asian countries. Despite very little language similarity, Vietnam is culturally and politically similar to China. Both have authoritarian governments run by their own Communist parties. Their people follow Mahayana Buddhism and also folk religions that venerate their ancestors. Singapore has many of the same characteristics of Taiwan. Over 75% of people in Singapore are ethnically Chinese. They are densely populated tropical islands located in the Pacific Ocean.
Region 8: Southeast Asia
Southeast Asia has two clearly defined groups of countries. One group of countries is located on the continental mainland, while the other group is spread across various islands off the mainland. The islands were heavily influenced by Arab traders and later European colonizers, so most people follow Abrahamic religions. Countries on the mainland were more influenced by Indian culture, so they are predominately Buddhist. In addition, four of the five adopted writing systems that originated in India.
Brunei is an outlier within Southeast Asia, since its government is an absolute monarchy with conservative Muslim laws similar to countries on the Arabian peninsula. Although it is quite wealthy, like Oman, it has few skyscrapers. The use of the Arabic script is also common in Brunei. The Philippines has some similar traits to Samoa since both countries have English as their official language and are mostly Christian. The Philippines also shares some characteristics with several Latin American countries as well.
Region 9: South Pacific
The South Pacific is a relatively small group of countries. Fiji is like Trinidad & Tobago since both countries have a significant amount of people with Indian ancestry, who were brought to these islands as indentured servants. As a result, both countries are quite religiously diverse, with significant groups of Christians, Muslims, and Hindus. Furthermore, it is one of the most prosperous countries in the region. Papua New Guinea is another unique country within the South Pacific. Although Papua New Guinea and Tanzania are far different from each other, both were colonized by Germany first before becoming British protectorates. They have similar laws and their infrastructure is not well developed. Both countries are mountainous and have a tropical climate.