From the project description [1]:

Wikipedia dumps raw database tables in a gzipped SQL format for the English language Wikipedia (enwiki) approximately once a month (e.g. dump from February 1, 2018)...By default, the script grabs the latest dump (available at https://dumps.wikimedia.your.org/enwiki/latest/), but you can also call the database creation script with a download date in the format YYYYMMDD as the first argument.

I'd guess the tool is working off an out of date article.

1) https://github.com/jwngr/sdow

Same, New Zealand to Faroe Islands through Italy.

Maybe both New Zealand and the Faroes reference Italy?

At the bottom of the page for each of the countries "Articles related to Italy" is a huge expandable section, with even more expandable sections inside. You can actually find both New Zealand and Faroe Islands in there.

If you view-source the Italy page, you can find a link to both of those countries.

It seems somewhat unfair. If it's not a directed graph, it means you can't actually navigate from the source to the target page by following these links...

edit: in fact, the author describes the goal of his project in another comment here: "my goal for the project which is to traverse the links as any human would be able to".

Parent was incorrect - the graphs are directed.

This is incorrect; links are considered a directed graph, as can be seen by reversing the start and end points of most paths.

Every single example I can find makes it painfully clear it is an undirected graph. Sets may differ going from one direction to the other simply because it is only trying to find a sample set of correlations, not an exhaustive set.

The graph is most definitely directed. One small example is Facebook -> Narcissism (1 path of 1 degree)[1] compared to Narcissism -> Facebook (8 paths of 2 degrees)[2].

[1] https://www.sixdegreesofwikipedia.com/?source=Facebook&targe... [2] https://www.sixdegreesofwikipedia.com/?source=Narcissism&tar...

Philosophy links to neither sexism or "The Demographics of Africa" (and while some older version might link to sexism, it seems unlikely that it ever linked to the Demographics of Africa"). Both of those do link to Philosophy, however.

Alternately it is directed, except when it doesn't find an easy route and uses an undirected result.

Click on "African People" in https://en.wikipedia.org/wiki/Philosophy#African_philosophy, you'll arrive at Demographics of Africa.

Likewise "Gender Bias" redirects to Sexism.