Free Will - an experimental approach. First try...
Dictionary Definition FREE WILL: Power of directing our own actions without constraint by necessity or fate.
Approach - I think we can attack this by looking at constraint.
So any experiment would try and show that some external agency acts on someone's interest (either for or against) without knowledge of the recipient causing a change to occur. What I thought of was a variant on the power of prayer experiments that have been carried out in the US.
You need two large equivalent groups. One of Atheists (A) and one of spiritual/theists (T). Additionally you need a third group (the rest of the world as it were) as a control (C).
We are going to look at death rates/longevity. Each group will be encouraged to support its members when they are ill. The theists by prayer, flowers & grapes, the atheists by flowers & grapes only.
We will look for a statistical difference in death rate/longevity.
T=A=C We appear to have free will. Further research necessary
T=A>C Placebo effect real
T>A>=C We do not have free will, something external is interfering with death rate/longevity
A>T>=C Parrots fall off perches!?