just-so story
なぜなぜ物語
Demarcation problem, philosophical question of distinguishing science and non-science
Factoid
False etymology, similar phenomenon in linguistics
Ipse dixit
Origin myth
pourquoi story
Richard Lewontin, who accused neo-Darwinists of telling just-so stories
Social dominance theory
Testing hypotheses suggested by the data
Urban legend
Woozle effect
https://en.wikipedia.org/wiki/Just-so_story