CASPer results provide medical school admission committees with valuable insights into how you will act as a doctor. As outlined on the CASPer website, this test allows applicants to demonstrate their “people skills” earlier in the application process instead of having to wait until the interview stage to show how they would interact with others in hypothetical situations.
So yes, you should take some time to prepare for this test and take it seriously, as your result combined with the academic requirements you submit will be used to determine whether or not you will advance to the next round of the application process.