Both Can Be True, part 9 of 12. Start with the series introduction.
"Every man is entitled to be valued by his best moment." Ralph Waldo Emerson, Representative Men (1850)
The moment
Someone's work is not good enough. You either soften it until the message disappears, or you say it straight and watch them fold. Neither one produces better work next time.

What is actually happening
You are sending one signal when the situation needs two, and the missing one is doing all the damage.
When someone receives hard criticism, they immediately run a question underneath the content: what does this say about how you see me? If the answer is "you think I can't do this," then every accurate point you made gets filed as evidence of your low opinion. They are not being fragile. They are answering the more important question first.
The most useful sentence in this whole series
David Yeager, Geoffrey Cohen and colleagues tested something almost absurdly simple. Seventh grade students got critical feedback on an essay. Attached to it was one note: I am giving you these comments because I have very high expectations and I know you can reach them.
Same criticism. One added sentence. In the first study, 71 percent of Black students who got the note chose to revise their essay, against 17 percent in the control group. Among students who already had low trust in their teacher, the gap was 82 percent against nobody at all. A second study found the wise feedback note improved the quality of the final drafts. (Plain summary of the findings.)
The sentence works because it answers the underlying question directly. High standards plus explicit belief. Remove either half and it collapses. Standards alone reads as contempt. Belief alone reads as flattery, and people can tell.
Why this is not softening the blow
It is the opposite. Assurance is what lets you be more specific and more demanding, not less. You do not need to shave the edges off the criticism, because the criticism is no longer carrying a hidden verdict about their worth.
• Amy Edmondson's work on psychological safety makes the same point about teams. Safety is not comfort and it is not lowered standards. It is what lets people ask for help, admit errors and seek feedback, which is what actually drives performance. She is blunt that safety without standards produces a pleasant team that achieves nothing.
The honest caveat
The sentence has to be true. If you say it while privately having written the person off, they will work out the gap within a month, and you will have spent your credibility. This is a technique for expressing real belief efficiently, not a technique for manufacturing it.
Try this week
Next time you give someone hard feedback, say why you are bothering. Out loud, in one sentence, before the content. It is the cheapest performance improvement available to anyone managing anyone.
Provided by Kai