Quite the opposite. You can find a few dozen links to the research. Maybe your professor was just an asshole. https://www.google.com/url?q=https://www.sciencealert.com/swearing-is-a-sign-of-more-intelligence-not-less-say-scientists&sa=U&ved=2ahUKEwjZjd6yp6_3AhX0pIkEHb5QDc8QFnoECAQQAg&usg=AOvVaw3bgqYSbmDy-3lPTZfBdU4A