The thing about claps is you can’t change your mind, like you can with hearts.
Kal Bassline
9787

When I click on the down arrow under a response, it gives me the option to "Undo applause for this post":

And when I hover over the claps icon at the end of a story I've applauded, an "X" pops up that you can click to remove your claps:

One clap, two clap, three clap, forty?

By clapping more or less, you can signal to us which stories really stand out.