Consumer Staples stocks tumbled Thursday, pulling the S&P 500 Index lower as investors showed signs of fatigue after three straight days of gains. Investors were jarred by the weak performance of some of the world’s biggest consumer product companies that reported earnings results. That sent shares of those companies into a tailspin. Although investors have been more muted in their response to companies that are reporting stronger-than-expected results so far, those that miss expectations or offer weak guidance have faced a harsh rebuke from investors. The S&P fell 0.6%, while the Dow Jones Industrial Average slipped 83 points, or 0.3%, to 24665. The Nasdaq dropped 0.8%.