How would individuality help the Strangers survive?

Question

Just watched Dark City. The Strangers are dying out, so they need to experiment on humans to find out what makes them individuals and not collectively minded like themselves. Is there any word out there as to why? That is, how does individuality help them survive? It seems the viewer is meant to take it for granted that without individuality you somehow die out. But then, the Borg are doing just fine :)

• Actually, there's some individuality among the strangers. As Mr. Book says - "If Mr. Hand wishes to make this sacrifice for the greater good, so be it." Clearly not something a true hive-mind creature would say - or even make sense of. Plus they occasionally disagree, and have the ability not to share information with each other.

Anyway - anyone have some idea? As with many cult classics, there might be some canon. So far I had trouble finding anything concrete.

Answer 1

There is no answer within the movie itself, or in any differing cut to my knowledge.

The only facts the movie states is that they are looking for the human soul, and that which makes us individuals, not the particulars of why. That said...

The most likely possibility to my mind is that their similarity is their vulnerability. Although the extent of their hive mind seems in question (as you point out an individual chose to sacrifice), there is little to distinguish one stranger from another other than the corpses they choose to inhabit and the names they pick up along with them. Even with that these seem more like token efforts to make themselves different rather than understanding individuality or actually being individuals. There's a number of theories in biological circles that diversity is what allows species to survive against different assaults over time. So either on a genetic or mental level they needed to be individuals again, and just didn't understand it at all, thus the experiments.

I prefer the answer that they had mentally stunted themselves to get to their tuning powers, which is more suggestible by the themes of the movie. My feeling is the very mental state that provided tuning to every single one made their supposed hive mind, but prevented them from conceiving or developing anything new (you don't really see Stranger children, just children corpses), and then susceptible to their own collapse.

Answer 2

There was an extensive prologue in the film's official novelisation. In short, the "Strangers" are a form of mental parasite. They possess substantial powers but their inability to think individually has drastically limited them.

After several hundred millennia drifting from one doomed species to another, they chanced upon the human race. They were very impressed by our individuality (as well as our various accomplishments in the Arts) and are busily experimenting on some samples they collected, in the hopes of determining how they can use this knowledge to achieve immortality

Prologue

It began with a small thing.
A fragment from a passing comet spun into the dim gravity of their planet. With the fragment came a dormant organism. The organism revived in the dark, dry atmosphere. Immediately it began consuming vital elements in the home planet’s fragile ecosystem. And slowly began killing the inhabitants.
They were a race as ancient as time itself. Until now their species had had a life span in excess of a thousand years.
They survived by just being.
Unfortunately their life form had no need, hence no means, for migration to another planet.
So they waited. And they died.
The aliens were nearly extinct when a stray explorer wandered into their orbit. This time they were prepared. The moment the explorer craft landed, they penetrated.
They easily mastered the visitors by assuming control of their alien consciousness. Essentially they became parasites living through their hosts. Then they left their doomed world for their hosts’ home planet. But by the time they arrived, their life support had broken down. Many of their hosts had already died.
Eventually, all of the host species were exterminated.
However, using alien technology developed by their late hosts, they managed to manufacture life. They replicated their hosts—enabling the remnants of their own race to survive. Then their last numbers filed onto the alien starship and soared into the unknown. Without even so much as a home planet they had become strangers in the universe.
The Strangers came upon a variety of possible worlds to colonize. But sooner or later their hosts expired.
And too, the Strangers were empty of purpose beyond survival. From their various conquests of alien worlds they had acquired disconnected technologies, sciences and techniques.
But as a whole it came to the same thing.
Boredom. As a species the Strangers shared a common consciousness. Their thoughts were limited to function.
And as they traveled the disparate corners of the cosmos the Strangers found that most life forms were the same. Species existed to exist. Almost always in colonies.
For the Strangers, existence was an endless, mindless quest for a benign host. The concept would never occur to them, but in a strange way they were searching for the perfect lover.
A symbiotic relationship that would nurture new life.
On their own extremely rigid terms.
Because after all, they did not have the power to conceive, merely to consume.
Which was sufficient. Until they chanced upon a small blue world orbiting a minor star. The planet abounded in two elements that were lethal to the Strangers.
One was water. The other was sunlight.
But the species native to the planet was unlike any life form the Strangers had encountered in an infinite universe.
Their consciousness had . . . dimension.
At first the Strangers attached themselves to the minds of their new hosts. Immediately, both died.
For a thousand years the Strangers studied the Humans—as they were named. And their envy grew.
Humans had private thoughts. Incredible fantasies. Dreams. Music. And most fascinating—individual memories. In fact, the sum total of these memories formed much of their complex intelligence.
Not that the Strangers were without formidable powers. They had the ability to control time. They easily controlled humans by simply willing them to sleep.
The Strangers could also shape, bend and change most matter to suit their needs. But their very lack of . . . imagination, narrowed the scope of these powers.
And so the Strangers set out to acquire human memories. To possess them. To be them.
Methodically, night after never-ending night, they gathered in a vast godless temple. There in the underground darkness they activated enormous secret dynamos—and went out to steal human souls . . .

Answer 3

As explained in this article from Film School Rejects, the Director's cut commentary addresses this by explaining that there is no answer to exactly why the Strangers are experimenting - or at least no answer that Alex Proyas (writer/director) has any intention of ever sharing.

Proyas left the Stranger’s reasoning behind the city and the experiment as simply “They’re looking for the human soul” in order to keep an air of mystery about them. “The film was more about the impact they had as a result of that experiment on human beings, so…if it begged for more answers then I always thought that was a good thing.” Proyas felt leaving the audience in the dark on a lot of the what and why of the Strangers made it a much richer film.