Hooks in storytelling are often discussed as a mechanism to engage readers, yet they are equally overused. Overreliance on hooks can take away from the depth of the story, causing a detrimental effect on a narrative. To use them correctly, it is necessary to understand them.
A hook, in a literal sense, is a curved piece of metal, usually with a sharpened tip. In fishing, hooks are used as they hook into the mouth of a fish and the tip forces the fish to comply with the will of the angler, yet should not break the flesh. The sharpness of the tip itself is enough to cause the desired effect without inflicting injury. The angler pulls on the hook, manipulating the fish to swim closer until it can be lifted out of the water, either on the hook or in a net. Whilst that method may work fine when fishing, it is not how hooks should be used in writing.
The purpose of a hook in a story is to grab the attention of the reader just enough so they keep going. The opening sentence is—along with setting the tone of the story—a hook used to encourage the reader to read the first page. That page, in turn, should contain enough of a hook to create a desire to read the opening chapter or section of the story, which then should propel the reader on through further hooks to keep reading, instead of discarding the tale. This works for novels, short stories, non-fiction books, articles and blog posts, even poetry and speeches. Get the opening right and the audience will want to continue.
It should be noted that hooks are simply a method to ensure your reader is interested enough to commit to the entirety of the piece, and should not be used to maintain their engagement beyond that. Rather, adding depth of character and theme will draw the reader further into your writing and captivate them fully. Hooks are the starting block, not the muscles that run the race.
An effective hook opens questions which the writer later needs to answer. If the protagonist is running through an alleyway covered in blood, the audience is wondering why and how they came to that point. That is a hook. If those questions are not answered, the audience feels cheated. That being said, the moment of reveal should be right for the story, and neither too soon nor too late. If a character always drinks a shot of vodka every Sunday at 2pm, that is enough of a hook to get you into the first few chapters, but should be replaced by something bigger. Holding back the reason until the final page of a novel will feel disappointing and anticlimactic, as the hook is not strong enough to pull a reader through the whole narrative.
Hooks are designed to pull you in, but past a certain point the reader should be pushing forward themselves. If the writing keeps trying to pull you in, over and over again, it is usually a sign that the narrative is not strong enough by itself. On the other hand, without a hook a piece can come across as inaccessible and therefore uninteresting. As with everything in writing, doing it well is a question of balance.