As young boys we were also dealing with our aggressive energies and the feelings that often ran counter to them, including empathy. These were tested by relationships with girls (though we typically had as little as possible to do with real girls) and with animals, which were often more a part of our lives. These films gave us several points of view on both.
Though the female leads were beautiful and screamed a lot, they were also often scientists themselves, and their relationships with the men around them were part of the story (especially in the last film.) And issues of humans v. nature (and what later gets called environmentalism), cruelty to animals and what separates humans from animals were all explored. The fright effects heightened emotional attention, and we were exploring other feelings, too. We learned behaviors and their consequences, in these vicarious experiences, and through identifying with characters (including the gill-man.)
These Creature films were science fiction in a very specific sense: the stories featured scientists, sometimes as heroes and sometimes as villains, and the pressures on them from various quarters were part of the drama. The stories were basically variations on King Kong (and its variation on Beauty and the Beast), but instead of Kong being captured for show business, the Creature was captured for science, including experimentation.
The role of scientist is one aspect that ties these films to others in the 1950s “bug-eyed monster” explosion, all very much inspired and commenting upon the atomic age. Though not directly related to the nuclear bomb theme of so many 50s monsters—he wasn’t created by radiation or unearthed by an atomic bomb or an invader from space—the Gill-Man was certainly part of the mood. (How could he not be? In the DVD docu, a theatre marquee for Creature From the Black Lagoon also announces “First Pictures of a Hydrogen Bomb Explosion!”)
All monster movies touched upon the Cold War theme of the Other—demonizing the different, the balance of real danger and imagined danger, of justifiable fear and manufactured panic. Also, most 50s monsters were versions of creatures in nature, and touched upon the sense of human’s twisting and violating nature by inventing and exploding the Bomb, which uses a secret potential of a natural force. Scientists were made more prominent by the Bomb, and the public saw them sometimes as admirable, and sometimes as violators of the natural order for daring to undercover these secrets. There was a sense that through them humans had taken on more power than humanity was equipped to deal with, and perhaps was ever meant to have.