Hook (or hook line)

A hook line is the first line of a social post — the line a reader sees before deciding whether to expand, swipe, or scroll past. It is the single highest-leverage sentence in any caption or carousel.

Strong hooks are short, specific, and emotional. They make a claim, name a tension, or pose a question that demands an answer. They do not introduce themselves ("In today’s fast-paced world…"); they do not warm up; they do not announce what is coming. They start at the point.

On Instagram and LinkedIn, only the first line or two appear above the "see more" fold. On TikTok and Reels, the first 1-3 seconds of audio are the hook. The mechanism differs, the principle is identical: get to the interesting bit before the audience leaves.

Hooks predict performance more than any other single variable. Two posts with the same body content and the same target audience will perform 5-10x differently depending on the hook. Optimising hooks is the cheapest engagement improvement available.