It requires a group because the movement is caused by changes in the net forces on the wand. If you are operating alone, you know you’re the sole cause of every movement of the wand, and there’s no trick to it. If you do it in a group, no one person can fully know all the forces on it. It’s in dissipating the responsibility throughout the group that enables the psychological trick to work.
HOWEVER
The more dissociated someone becomes from their own influence on the wand, the more external the wand’s behavior appears. Providing insight into subconscious desires becomes a reward for developing this psychologically dangerous dissociation. The user may actually convince themselves that some completely external force is responsible, allowing the dissociation to become coupled with an almost psychotic delusion.
And those dangers are even discounting the demonic dangers! According to the “magic,” the ouija board channels spirits to come among practitioners. If such spirits are demonic (and to whatever extent they are real, they would have to be demonic since divine spirits would not participate), this is merely inviting demonic influence. The spirit does not enter any given individual. However, when practiced alone, the spirit’s influence is only through a single person. Thus, the spirit comes to be entirely within a person. This, then, isn’t merely influence, but possession. Even ancient practitioners considered going solo to be taboo for this reason. (If you don’t believe in demonic possession, you could suppose this is merely an explanation for why solo practitioners went psychotic.)
Seems strange. I guess I have never tried because I never believed the wand was influenced by anything/one except the participants. Truly I believe in spirits, but just not that a whole group could be free enough to allow their influence.
Your story is compelling evidence that groups can do just that. Gives me a reason to not try.