It's not a perfect test. Some of the most human people I know would be upset when asked about their mother.
Was this in response to the theory of mind?
Theory of mind is the fact that humans have an understanding that different people have independent minds. Even with the "smart" other animals like gorillas and dolphins and parrots and things that can be taught to "talk", that exhibit problem solving, etc: to date every test attempted to evaluate their theory of mind is negative. Apparently also this is something that develops around 5 years of age in humans.
It's why gorillas can sign and let you know what they want or how they are feeling, but they have never been observed to ask what you want or how you are feeling.
A simple test is: show a kid a picture of two people (say, Alice and Bob), a box, a basket, and a cookie. Show the kid that Alice puts the cookie in the box, then leaves. While Alice is gone, Bob moves the cookie to the basket. Have Alice come back, and ask "where does Alice look for the cookie?" Without theory of mind, Alice looks in the basket. She doesn't have independent knowledge - she knows what the kids know.
With theory of mind - the kid will say Alice still looks in the box, because she has no other knowledge: it's a realization that there is independent mind.
That recognition of "other mind" is, so far, the most distinguishing characteristic of humans: above emotion, above problem solving, above communication.