"There is, in science fiction horror movies, a figure of alien opposed
to that of the irrepresentable and all-devouring monster of Scott's
Alien, a figure immortalized in a whole series of films from the early
1950s whose most famous representative is The Invasion of the
Body Snatchers. An ordinary American wanders somewhere in the
half-abandoned countryside, when his car breaks down, so he goes
for help to the closest small town; soon, however, he notices that
something strange is going on in the town - people behave in a
strange way, as if they are not fully themselves. It becomes clear
to him that the town is already taken over by the aliens who penetrated
and colonized human bodies, controlling them from within: although
the aliens look and act exactly like humans, there is as a rule a tiny
detail which betrays their true nature (a strange glimpse in their eyes;
too much skin between their fingers or between their ears and heads).
This detail is the Lacanian objet petit a, a tiny feature whose presence
magically transubstantiates its bearer into an alien. In contrast to
Scott's alien who is totally different from humans, the difference is here
minimal, barely perceptible - and are we not dealing with the same in our
everyday racism? Although we are ready to accept the Jewish, Arab, Oriental
other, there is some detail which bothers us in the West: the way they
accentuate a certain word, the way they count money, the way they laugh.
This tiny feature renders them aliens, no matter how they try to behave
like us."

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How to Read Lacan
5. Troubles with the Real: Lacan as a Viewer of Alien