In South Dakota, what is undue influence in estate planning?

In South Dakota, undue influence consists of someone taking unfair advantage of another, especially when they hold real or apparent authority over them. An example of this is a caregiver for an elderly person who isolates them from their family and convinces them to leave most or all of their assets to the caregiver. Essentially, the person exerting undue influence takes unfair advantage of another person’s frailty of mind or body to get an unfair advantage over them. Undue influence can come from an outsider, such as the caregiver, or could come from a family member.