Better keep it simple.
The problem with telling people why you can't make their event is that you're usually sort of lying.Think about it: If your best friend invited you to your favorite band's concert, but you'd already planned to be at book club that night, you'd somehow weasel your way out of discussing "Pride and Prejudice" and make it to that concert.
But if your coworker invited you to watch a really depressing documentary? "Sorry, but I've got book club tonight, and I just can't get out of it."
Which is why behavioral investigator Vanessa Van Edwards' best tip for turning down an invitation makes so much sense: Don't offer an explanation. None. Not a word. Just say "no."
Too often, people try to come up with a reason - real or invented - why they're declining an invitation and quickly wish they hadn't.
In a video posted on Van Edwards' Science of People blog, she explains how this strategy can backfire:
"People will argue with you. If you say, 'Oh, I can't come to the party because I've got to get home early for the babysitter,' they'll say, 'Oh, don't worry. You can come early and I'll let you leave before 8.' And then you're in trouble.
She concludes: "Say 'thank you' and just say 'no.'"
Van Edwards' advice is similar to advice that etiquette expert Rosalinda Oropeza Randall previously gave Business Insider. Randall recommends keeping it simple: "It's not going to work out tonight. I'm so sorry."
"Excuses can really get you in a deeper pit" as you try to cover up one white lie with another, Randall told Business Insider in February.
When you really think about it, you're not offering an explanation to make the other person feel better about missing your presence - you're doing it to make yourself feel better about declining.
So tell yourself you're entitled to some privacy. Practice saying "thanks" and "no." Over time, it'll feel more comfortable.