I would say it is caused by desire and intent; awareness. I apologize as I have difficulty verbalizing these less tangible concepts, which have most often come to me conceptually in meditation and validated through experience and contemplation.
I wholeheartedly recommend exploring Oxal’s channeling in the archives. Additionally, I made a post that may be of interest: The Nature of the Universe and the Relationship Between the Physics of ‘Reality’ and the One Reality
Edit: Perhaps considering emotions in the context of alignment may help, while picturing Indra’s Net. It is hard to maintain harmony with the whole with misaligned momentum. One may try and bring, either willingly or forcefully, others along for their ride – but ultimately, we are One. One being, one momentum, in unity.