Certainly, such things as body language and the subconscious mind should not be underestimated. It is said that as much as 80% of all communication is non-verbal, while the subconscious mind remains something of an unexplored territory.
However, what I observed while working amongst what might be termed "indigenous persons" could not be put down to body language, and occurred far too frequently to be coincidence (or the result somebody eating a meal of indigestible food, then suffering a bad attack of flatulence!). Admittedly, some of it was a direct result of their highly developed powers of observation, added to a lifetime of experience - leading to what might at first sight seem uncanny skills at tracking (as in the case of Australian Aborigines, or the San people of southern Africa). Even so, there were still many occurrences that went beyond what observation and experience could have explained.
Okay, "Supernatural" is a rather loaded term. What I repeatedly saw during my time in Papua New Guinea, though, defies explanation from scientific thought at its current level of understanding. I would sure like to know what was going on!