Some (but definitely not all) so-called soft-skills can be assessed through hard-skills. Coding, as a hard-skill for instance, can be relatively straightforward to assess. You present the talent with a coding problem. Depending on their ability to rectify the mistake and the time (to a lesser extent) they take, the assessor can gauge the talent’s coding skills. Hard-skills, check.
Depending on how a talent solves the problem, the assessor can derive some insights regarding soft-skills. Does the talent take much initiative? Do they use a creative approach? What’s their problem-solving mindset? How far are they willing to go to solve the problem?
In some cases, soft-skills can be assessed through hard-skills.