“It’s somewhat surprising that typos and grammatical errors hold this much power given the speed and frequency of written communication that characterizes the digital age. Despite our ‘sent from my iPhone’ disclaimers, it appears we should still be diligent about avoiding written mistakes. Especially if were writing to a conscientious introvert whose not very agreeable. Their the wrst.” On proving something that we all suspected to be true: less agreeable people care the most about grammar.