Risa

This is most evident in the TOS episode "The Galileo Seven". It's a horrible scenario: Spock is in command of a marooned crew on a hostile planet. He fails to take both a scared crew and an aggressive native species of spear throwing giants, into consideration. He makes one logical survival choice after another, failing to address everyone's irrationality at every turn, which ultimately costs two lives. Nothing more than the crew's faith in the chain of command (and perhaps faith in Scotty's engineering skills) holds this disasterpiece together.

And Vulcans in Trek kind of just get worse from there. You'd think they'd eventually learn to take "irrational actors" into account with assessing situations, but they don't. While that seems far-fetched, our economists here in 21st century Earth don't either.