Some interesting overview and history of the 'deceptively easy' Wason Selection Task in today's Nautilus:
Perhaps this test and its implications, by a man who treated "reasoning as an enigma" is even extra pertinent in a week that people are engaged in especially important political decision-making! From his 2003 obituary: “His aim was to reveal a surprising phenomenon—to show that thinking was not what psychologists including himself had taken it to be.”
[If by any chance you're not familiar with the task, the article contains an interactive video you can play with. And it's a fun test to run by students and adults at various levels.]
Also, as with many puzzles I enjoy, language or words, in addition to strict abstract reasoning, potentially come into play here, as the article indicates.
[ADDENDUM: just realized, this article is a RE-run of a piece Nautilus ran in May 2015]