The idea that conducting a survey explains why people check their travel documents in advance is an oversimplification. Historically, travelers have long anticipated identity checks, not because a survey indicated it, but purely out of practical necessity and to avoid costly problems.
The record shows that passport or visa requirements have always prompted vigilance long before the era of online surveys.
We've seen this movie before: people learn from their mistakes or others', shaping their behavior.
For example, being refused boarding due to an expired passport is a lesson that is not forgotten, and it precedes any study on planning habits.
This survey only notes a well-established habit; it does not create it.