Robert Murphy, an online marketing representative in San Francisco, was invited to a business meeting with his boss and six colleagues a few weeks ago. He had attended previous meetings on the subject, and he prepared with additional research. He brought a thick sheaf of notes and contracts with him to the conference room. Ever felt like an idiot in a meeting at work or clammed up at a cocktail party? New research from Virginia Tech shows that many people are actually less intelligent in small group settings. Elizabeth Bernstein has details on Lunch Break. So what did he contribute to the discussion? Absolutely nothing. "I just sat there like a lump, fixated on the fact that I was quiet," says Mr. Murphy, 31 years old. Have you ever clammed up at a party or found yourself tongue-tied at a meeting for fear of saying something stupid—even though you consider yourself at least as smart as anyone else in the room? Research from scientists at the Virginia Tech Carilion Research Institute offers an explanation of why many people become, in effect, less intelligent in small group settings.