Mapping Global Friendship Ties

By Johan Ugander on Monday, March 19, 2012 at 6:05pm

In February 2004, Facebook launched as an online social network for connecting a small college community in Cambridge, Massachusetts. Eight years later, Facebook has become a truly global service, providing 845 million active users – from Andorra to Zambia, from Guinea to Guyana – an easy way to stay connected with the world around them.


As Facebook has grown, the global network of friendships has begun to reveal fascinating and previously unobservable details about the rich social weave that envelops our planet. This allowed Paul Butler to produce a beautiful map of Facebook's social graph in 2010.


But how, really, is the world of Facebook connected? How strong are the ties between different segments of society, across geography and demography? These were questions that my colleagues and I aimed to investigate when analyzing the Facebook social graph last year, discussed in a previous post.


In that study, we included a brief analysis of the friendship ties between countries – how the world exhibits a complex community structure on a grand scale. For example, Australia and New Zealand displayed many close ties, and we observed similarly strong ties between the Scandinavian countries of Denmark, Norway and Sweden.


In particular, we were struck by an especially interesting structure that emerged: when mapping the friendship ties connecting once-expansive trade empires such as Great Britain, France, Spain, Portugal and the Netherlands, the maps bear an uncanny resemblance to the borders of the former empires, long since past. Despite long periods of independence in some instances, the social fabric of these countries frequently reveals a lasting impression of their former history.


Take, for instance, the friendship ties of modern Great Britain:


On this map, the colors indicate how strongly each country is connected to Great Britain on Facebook – the darker the shade of blue, the stronger the friendship connections. Australia and New Zealand hold clear strong ties, but we see that large parts of East Africa also hold strong ties, especially former British territories such as Nigeria, Ghana and Sierra Leone. In South America, we see ties with Guyana, the modern sovereign republic that was once the former colony of British Guiana.


Next up, France:


Here we observe strong ties from West African countries, with the notable exception of the previous British colonies mentioned above. But connections with Djibouti and Madagascar, both former French territories, are also visible. From France's perspective, 16% of their international ties are with Africa, compared with just 9% of Great Britain's international ties, 6% for Portugal, 6% for the Netherlands, and 4% for Spain. Of all the ties leaving Africa, 9.1% are with Great Britain and 8.9% are with France, compared with just 1.9% for Spain, 0.7% for the Netherlands, and 0.7% for Portugal.


In South America, we see a lone strong French tie: French Guiana.


Now, Portugal:


Portugal's empire was once expansive. Most obvious on the map is Brazil – 17% of Portugal's international ties are with Brazil alone. In Africa, we see strong residual relationships with Mozambique and Angola in southern Africa, and Guinea-Bissau in the east, all former territories of Portugal.


Turning to Spain:


The connections from South American countries to Spain are impossible to miss. About 28% of Spain's international ties are with South America, compared with 20% for Portugal, 5% for the Netherlands, 5% for France, and 3% for Great Britain. Also notice the strong Spanish ties with North Africa. Less visible are the strong ties between Spain and Equatorial Guinea, a former Spanish territory and today a small coastal nation in Africa.


Lastly, the Netherlands:


The Netherlands is another small European nation that once had a significant trade empire. There are strong connections between the Netherlands and Suriname, the former territory in South America, and the adjacent former Guinean territories. But few ties exist elsewhere in South America. There are also links with Ghana and other coastal West African countries, where the Dutch had early trade relations.




We see from these maps that human relationships form a complex, global tapestry that is patterned by intricate historical ties. Ties between countries often run deep, with early imprints such as language likely laying the foundation for modern international business and tourism.


By examining how connections on Facebook today truly span the globe, we see that the service has formed connections far beyond what college students in Cambridge, Massachusetts could have imagined.