The dictionary definition of “sinister” would likely say that the word means something evil, or something that threatens or promises evil or the foreshadowing of dangerous people or events.
early 15c., “prompted by malice or ill-will, intending to mislead,” from Old French senestre, sinistre “contrary, false; unfavorable; to the left” (14c.), from Latin sinister “left, on the left side” (opposite of dexter)https://www.etymonline.com/word/sinister
Sinister, today meaning evil or malevolent in some way, comes from a Latin word simply meaning “on the left side.” “Left” being associated with evil likely comes from a majority of the population being right-handed, biblical texts describing God saving those on the right on Judgment day, and images depicting Eve on Adam’s left.https://www.merriam-webster.com/words-at-play/sinister-left-dexter-right-history
So the Latin origins were simply about the left, or something on the left side. But then there were negative connotations associated with things on the left. Some say that passages in the Bible where you should not let your left hand know what your right hand is doing (Matthew 6:3), or in the Old Testament, where the righteous would sit at the right hand of God.
During the Middle Ages left-handed individuals were actively opposed, indeed being left-handed was for some an indicator that a female could be a witch. Left-handed people were viewed as distrustful or worse.
Educators in Victorian times allegedly tied the left hand behind the back of students to force them to write with the correct hand. After all, right is right, right?
I’m left handed. And I remember the head teacher of my school checking the handwriting of my class (perhaps 9 or 10 years old) and him praising my handwriting to my teacher: “Hmm. Good handwriting. For a left hander.”
Think about the superstition of throwing salt over your left shoulder if you have spilled it. Why the left shoulder? Because the devil, or a demon is lurking there. Think about the imagery of having an angel and devil on your shoulders. Most of the time the devil is on the left.
The British Pantomime, which inherited a lot from the 16th Century Italian Commedia dell’arte, also had the villains enter or exit from stage left – from the right-hand side as the audience would look at it.
The evil connotations of the left, or something appearing from their left, can also be seen in the movies – and this fascinating article from NO FILM SCHOOL shows how the idea of the villain appearing from their left seems to be ingrained into our psyches.
So when the man appears from his right and looks in the window – it seems fine. When he appears from his left, we feel suspicious!
Now evil from the left of the stage (audience right) is not a rule – so you won’t see it all the time. But if we subconsciously are unsure about a character from their left, why not utilise it?
SINISTER MOVIE POSTERS
And finally – the movie poster.
Here are a selection where there is a very deliberate use of light and shadow. Note that the shadow is on the left of the subject: the evil side. Light (or goodness?) comes from their right.
Not all of the above posters are showing clear cut evil characters. Clint Eastwood’s character in UNFORGIVEN is conflicted with moral ambiguity. The Terminator in T2 first appears as evil, but we realise he’s changed. In TERMINATOR 3, Arnold is lit from the right – but the left side of the new Terminator’s face is in darkness.
THINGS GET MURKY:
In these two examples THE DARK KNIGHT and CASINO ROYALE, the main protagonist is a good guy. Right? So what’s that “evil” shadow all about? Discuss.