It seems we've been getting it wrong when we say sorry. Evolutionary psychologists have spent years researching the art of the apology, and finding out how to do it most effectively. RNZ's Karyn Hay talked to some experts.
Professor Yohsuke Ohtsubo from Kobe University in Japan has been working on the art of the apology for more than a decade. He collected data from primatologists, who have noted that our animal cousins show particular patterns when reconciling after disputes.
"They found monkeys and apes are really good at making friends again after conflict. After the conflict they go to their partner as soon as the conflict ends, and some primates kiss each other, and some hug each other, but they approach their partner and make friends again," Ohtsubo says.
"We usually say 'sorry' and reconcile - but in some cases just saying sorry is not enough - that's our research. We sometimes need to incur some cost in making apologies.
Ohtsubo says the cost can take any form, it could be offering to repair the damage caused, or sacrificing time or another event we were looking after, to show the importance of the apology.
"The cost communicates the sincerity of your apology. If you really value the relationship and you want to restore that relationship you can pay the cost, because you value the relationship more than the cost."
An example is the 2013 online apology by Japanese pop star Minami Minegishi, who shaved her hair and tearfully begged to remain in the band after breaking its rules.
"That's a kind of costly apology, and she successfully convinced her fans, and she is still in her group," Ohtsubo says.
Social and environmental psychologist Cindy Frantz from Oberlin College in Ohio agrees there's etiquette to making an apology count.
"People really need to feel that you understood what you did wrong, and they need to feel heard."
She says often when people realise they've made a mistake or hurt someone they try to apologise quickly to try to make the situation right, but this is not always the best time for it.
"People can actually sometimes have the feeling that they're not ready for you to apologise, because they haven't had the chance to tell you how upset they are or how much it hurt them.
"What we found was that when apologies came a bit later ... people were more likely to be satisfied, because they were more likely to have explained to the transgressor what they were upset about, and they were more likely to feel like the transgressor actually understood."
One key ingredient is for the victim to not feel that the wrong will be done again, she says.
"And I think pain or cost is one way to show that the relationship matters, and that you're going to take it seriously, but I think there are other ways as well."
Frantz says apologies should always begin with a thank you from the person apologising, to the victim. But Franz says applying a cookie-cutter rule isn't helpful.
"I think there's no one way to do it. Saying thank you is one way of saying 'okay, I hear you and I'm taking seriously what you say - thank you for correcting me, thank you for pointing out my error', so I think that can be really effective, but I think that depends on the situation."
One case of an apology really mattering is a prisoner appearing before a parole board, where they are recommended to take responsibility for their actions and to not make excuses for their crime if they want their penitence taken seriously.
"When we give excuses, that's in my opinion the opposite of an apology," Frantz says, "and the listener doesn't have any reason to believe that you took responsibility and won't do it again.
"That's one of the most important things going on in an apology, if there's been a wrongdoing we want to believe it won't happen again. So responsibility is key."
Frantz says research shows women and people in low power relationships often use 'sorry' as a placation; "it's a sort of verbal bowing down rather than an apology, even though the words are the same, it's filling a different purpose."
Public apologies can be vital but fraught and especially hard to get right, Frantz said.
"When someone is making a public apology, especially a very public figure, there's so many reasons to do it - damage control, are they doing it just because their PR person suggested it would be a good idea to help with the polling numbers?
"Even if the person really means it, it can be really difficult for the public to tell that."