How do you disable emotions?
"Well, that's it, then - you had a controlling mother who had
certain expectations, and if you strayed from them, you were shut
down. That's why you're afraid to care about anything - and why you
can't express yourself."
Human emotions can be quite an obstacle. Fear can make you
unable to face the danger. Compassion can prevent you from shooting
the dog even if it's necessary. Love can make you crazy, dumb or
lead you straight to the Dark Side. Let alone it hurts. And then
there are such things as anger or hatred.
Anyway, emotions cloud your mind and impede logical thought. So,
what do you do with them? Well, in the world of fiction you can
find a way to relieve yourself of this burden. Via some sort of
training or some Applied Phlebotinum you can completely remove your
capacity to feel emotions.
Results and consequences depend on the author and how exactly
the emotions are suppressed. Portrayed as a good thing, Emotion
Suppression can be used to enter Heroic Safe Mode, to escape Mind
Rape or simply to concentrate on the fight clearing your head of
unimportant thoughts. This kind of supression is almost always
temporary and always voluntary. Sometimes it is portrayed as a bad
thing. In that case the character in question can at best hope to
be an a loner or an Emotionless Girl not knowing This Thing You
Call Love. At worst, the character will be put in a sort of Uncanny
Valley, being human in appearance but not human in behaviour. Any
sort of permanent Emotion Suppression will probably turn out this
way, Bonus Points if it is not voluntary. This trope can also be
carried out on a massive scale. There can be a human or alien
culture where every representative has their emotions supressed.
This situation also has little chance of being undeniably good. At
best, (other) humans will just leave it as it is, perhaps after
some demonstrations of how emotions can be useful. If it's done by
an Evil Overlord or... uh... a caring and benevolent ruler who is
unable to paint smilies on their subjects' souls but at least wants
to remove tears from there, you've got a ready dystopian setting.
This is part of the basis of The Stoic and the Emotionless Girl,
Ice Queen and The Quiet One characters, The Baroness, the Deadpan
Snarker (and Little Miss Snarker), the Broken Bird, the Sugar and
Ice Personality and the Aloof Big Brother. Compare and contrast
Getting Smilies Painted on Your Soul or Lotus-Eater Machine:
Emotion Suppression does not make you happy, it just makes
you, well, emotionless or lets you get rid of certain emotions.