An electronic device with a display, a touch-sensitive surface, and one or more sensors to detect intensity of contacts with the touch-sensitive surface: detects a first gesture that includes concurrently detecting a first contact and a second contact, detecting an intensity of the first contact, and detecting an intensity of the second contact; and, in response to detecting the first gesture: in accordance with a determination that the first gesture meets first operation criteria (including a criterion that is met when the intensities of the first and second contact satisfy a respective intensity threshold), performs a first operation; and, in accordance with a determination that the first gesture meets second operation criteria, wherein the second operation criteria are capable of being met when the intensities of the first and second contacts do not satisfy the respective intensity threshold, performs a second operation that is different from the first operation.