"Half-full/half-empty" type test, please explain?

Question

This question is for those who know psychiatric theory as practiced in the 1970's. At least educated guesses please...

Once, after I had a head injury as a child, a shrink who had seen a family member asked to see me, to look for ill effects. After I entered the office, this dude produced a jar of shelled peanuts and hands it to me. "Here, have a snack."
I pour myself some peanuts and start munching, but he takes the jar again and says, "No, eat them like this." He pours more into my hand until there's a huge heap there, pours himself a similar handful, and mimes eating the whole thing.
I thought it was outrageously funny that this important man would ask me to do this. I tried for a bit to eat the whole handful, without much success. Then he asks some forgettable interview questions. Later he says he found no ill effects.
What was this "half-full" test about? If it was about suggestion or authority, my finding it humorous influenced my response and ruined it.

ok the first two answerers obviously read the title but not the question. This question is about a test of the same TYPE as the "glass of water" test, but not about the "glass of water" test itself. Obviously it was trying to observe something different; while the "glass of water" test tries to tell an "optimist" from a "pessimist," the test I experienced was geared toward some other aspect of my "psyche." My question is, what was this particular test trying to measure, as it obviously wasn't my outlook on life.
The best possible answer will come from someone familiar with the methods used by shrinks in the 1970's. Since this test was the first part of the examination, I expect it was common at the time.

Answer 1

Usually when this question is asked, the person is looking at your perception of life. If you see a half glass of milk to be "half - empty" you tend to have a negative outlook. If you say it's "half-full" you tend to see things in a more optimistic view.

Hope this helps!

Answer 2

Green

Answer 3

I think that it's really a philosophical notion that if you see the glass as half-full, then it represents optimism. If you see the glass a half-empty, then it represents pessimism.