Aaron Lazare, the former dean chancellor and dean of the University of Massachusetts Medical School, wrote a book about the apology, which he called one of the most profound interactions two human beings can have with one another. Research by Lazare and others suggests that effective apologies—meaning those that are accepted by an offended party—all tend to share a set of underlying features. For close relationships in particular, studies have shown that one of the most important elements is timing: When people make the common mistake of saying they’re sorry too quickly, they can miss a crucial step towards reconciliation.

The impulse to apologize instantly may stem from a cultural credo that action is always better than indecision—and that waiting implies apathy. “We are primed to react immediately to everything,” said Frank Partnoy, the author of Wait: The Art and Science of Delay. Like the skilled tennis player who waits as long as possible before returning a serve, Partnoy argued, strategic stalling in apologizing often yields the best results: “We feel we need to apologize right away, in the same way we feel we need to respond right away to texts, emails, and 24-hour news.” But if someone commits a serious transgression—say, cheats on a spouse—it’s best to apologize only after the victim has had a chance to “yell and vent” and fully process the betrayal, he said.

Past research has shown that a key part of a successful apology is assuring the victim that the bad behavior won’t happen again. “When we’ve done something wrong, we tend to be self-focused,” explained Cynthia Frantz of Oberlin College, who authored a landmark study on apology timing titled “Better Late Than Early.” “You actually should be more focused on the other person, making sure they really believe that you get what you did wrong.” Without that emphasis on the other person’s emotional state—and the promise of change—an apology sounds insincere.

In 2004, Frantz asked 83 college students to respond to an ordinary social conflict—forgetting to meet a friend for a party, but going on their own—and then to imagine that the friend had apologized at the very beginning of a conversation, after the participants had a chance to voice their feelings, or not at all. Respondents had the most positive reactions to an apology delivered after they’d had the opportunity to express themselves and feel heard by the other party. But Frantz cautioned that the apology curve is most likely U-shaped: Apologies that come too late, like those that come too early, are likely to fail; the sweet spot is somewhere between the two. “[This] could be an hour, a day, a week,” Frantz said. “It depends entirely on the circumstances and the nature of the relationship.”

It may be that later apologies work best for more discrete conflicts, while earlier ones prevail for deeper, open-ended ones. For a 2013 study published in the Western Journal of Communication, researchers videotaped 60 heterosexual couples discussing preexisting relationship issues, like annoying habits or disagreements over how they should spend their time together. For conversations shorter than 10 minutes, the study found, people tended to be more satisfied with a later apology from their partner. But if the conversation lasted longer than 10 minutes, the couples tended to judge their disputes as more damaging— more likely to touch on questions of trust and jealousy, for example—and preferred an apology earlier in the discussion.