Scientific American – “… Adam Mastroianni and his colleagues found that only 2 percent of conversations ended at the time both parties desired, and only 30 percent of them finished when one of the pair wanted them to. In about half of the conversations, both people wanted to talk less, but their cutoff point was usually different. Participants in both studies reported, on average, that the desired length of their conversation was about half of its actual length. To the researchers’ surprise, they also found that it is not always the case that people are held hostage by talks: In 10 percent of conversations, both study participants wished their exchange had lasted longer. And in about 31 percent of the interactions between strangers, at least one of the two wanted to continue. Most people also failed at intuiting their partner’s desires. When participants guessed at when their partner had wanted to stop talking, they were off by about 64 percent of the total conversation length. That people fail so completely in judging when a conversation partner wishes to wrap things up “is an astounding and important finding,” says Thalia Wheatley, a social psychologist at Dartmouth College, who was not involved in the research. Conversations are otherwise “such an elegant expression of mutual coordination,” she says. “And yet it all falls apart at the end because we just can’t figure out when to stop.” This puzzle is probably one reason why people like to have talks over coffee, drinks or a meal, Wheatley adds, because “the empty cup or check gives us an out—a critical conversation-ending crutch.”…