What has been observed, again and again, is the power of a social group to accomplish phenomena which are not easily understood. Healing without medicine, mass mental and physical illness, even speaking in tongues Eulalia. It does happen. the consistency of the phenomena- qualities of sound, etc, mean it is not a one off nor is it faked. It is another state of consciousness whether internally or externally induced
I've been present quite a few times when people have spoken in tongues. The first time freaked me out a bit---well okay---everytime freaked me out a bit, but this is what I saw happening.
The first time, I went with a friend to a youth group bible study. Toward the end of it, they got up in a circle and linked arms to waists. I was in that circle, and they started to pray individually. Some out loud softly, and some silently. But the circle started to sway. It was hypnotic, and it startled me. I didn't like it, as the feeling was of merging with this group of strangers and becoming one. I didn't know what that oneness should be based on, so I watched their faces. As time went on, I head the occasional 'praise Jesus' or 'praise god' being uttered. Then it went sing-song 'praaaaaise jeeeesus' 'praaaaaaaise God'. Kids that I knew were changing right before me. Many had their eyes closed, which I'm sure intensified the effect of the swaying. After a while they started speaking in tongues.
It was very clear to me, even as a teen, that these people had put themselves into an altered state of mind.
After that, I witnessed other approaches. Some weren't as dramatic, but it was still the same. They changed into this altered state and spoke in tongues. That was holy spirit, according to them.
Yet it is not particular to Christians! Many non-Christian faiths do the same thing. Whirling Dervishes speak in tongues. I don't suppose we have to look too far to see what causes their altered brain states. Inuits have also been known to speak in tongues.
It doesn't take much to understand that tongues does not need to be the only manifestation of this state. Whatever the culture dictates can be achieved. Perhaps if a Christian saw a Whirling Dervish speaking in tongues, they would conclude it was satanic, not even realizing how similar the experience is to many Christians. Or perhaps a person begins to mimic the actions of an animal. That would look a bit scary to the average Christian, but that Christian may not flinch if they see their own dancing about or convulsing on the floor.
READ.