> However I don't know if that reflects some deeper truth about the world, or just my bias in how I answer the questions.
It's the same reason why you always end up on "Philosophy" if you're browsing Wikipedia and consistently follow the first link in each article. Here's the path for "Airplane":
Airplane
Fixed wing aircraft
Aircraft
Vehicle
Motion (physics)
Natural science
Science
Knowledge /* we know where this going... */
Fact
Proof (truth)
Argument
Philosophy
I think that website cheats a little bit. The first link in "Science" is not "Knowledge" but "Latin", where it's describing the root of the word "Science". If you follow it properly, you'll find that even the article for "5 Whys" doesn't go to Philosophy:
5 Whys
Technique
Technology
Tool
Goal
Animal
Eukaryote
Organism
Biology
Natural Science
Science
Latin
Italic Languages
Indo-European Languages
Language Family
Language
Human
Taxonomy
Ancient Greek
Greek Language
Indo-European Languages // Infinite loop!
That path seems to go in the same direction, but then it diverges in Science, mostly due to the first sentence on that page, where [Latin] and [knowledge] are links:
> Science (from [Latin] scientia, meaning "knowledge") is a systematic enterprise that builds and organizes [knowledge]...
It happens again in Taxonomy, which otherwise would surely lead to Philosophy from the [classification] link:
> Taxonomy (from [Greek]: τάξις taxis "arrangement" and Greek: νομία nomia "method"[1]) is the science of identifying and naming species, and arranging them into a [classification].
On our way to Philosophy we are constantly confronted with Latin and Greek concepts, because Rome and Greece are where many of the concepts in Philosophy originated.
I think the wikipedia game specifically excludes words in parenthesis and italics. Following those rules you actually do get to Philosophy, and you also get to Philosophy from Indo-European Languages.
It's the same reason why you always end up on "Philosophy" if you're browsing Wikipedia and consistently follow the first link in each article. Here's the path for "Airplane":
Try it yourself: http://www.xefer.com/wikipedia