"Strange Behaviour" is a lot better than I'd expected it to be. It has some startling imagery, some genuinely frightening scenes, and finally manages a sense of atmosphere.
It is also an original twist on the slasher formula that was probably stale even in 1981 - at least if the parody film "Student Bodies", made that same year, is anything to go by. Seasoned horror junkies have seen hundreds of slashers at least. We all know the trope of the killer wearing a distinctive mask, which is often removed in the final moments to reveal the killer's identity. But in "Strange Behaviour", the movie has more than one killer, and in fact deals with the question of mind control. In this movie, any of the younger characters can kill at any time, so it's not a question of whodunit. It's more like who's going to go crazy next.
For its cool ideas, occasionally shocking imagery and at least one frightening scene, "Strange Behaviour" is a winner. Unfortunately it is held back by some narrative incoherence and charisma-less lead performances. I still say check it out.
Lastly, I want to say something about the movie's unusual pedigree. It's an American production that was meant to be filmed in Australia, but when the filmmakers couldn't find any cities in Aus that resembled the screenplay's setting in Illinois, they moved the production to New Zealand! How is NZ any more or less Midwestern USA than Australia? And, to top it all off, the movie is considered an "Ozploitation" flick?
No wonder the plotting is a little confusing. The cast and crew probably didn't know where the hell they were, or were supposed to be, or what they were actually making.