The title is inconsistent with the article title, and even the article title seems inflated to what it describes.
As I understand it, the experimental group played a game they couldn't lose (rigged) and adults gave them "hints." The kids [correctly] identified that they weren't dependent on the adults' help in that group.
However, there doesn't even seem to be a link to the actual study anywhere, so I can't even check what this research actually is.
The "establish selective trust" phrase is much more accurate than just "trust" -- in fact, the current title on HN in strictly incorrect. The preschoolers don't have problems trusting. Rather, you could argue that they're more trustworthy when they never lose. It's the "selective" part that's important. (That said, this feels a bit pedantic to me, and it seems as if no one is confused by the difference in wording.)
The "Let your kids lose:" prefix on the SD headline (and not in the peer reviewed publication) could cut either way -- it might be link bait, but it's also not inconsistent with the researchers' advice.