From The New Yorker:
Psychologists have long known that first impressions really do matter—what we see, hear, feel, or experience in our first encounter with something colors how we process the rest of it. Articles are no exception. And just as people can manage the impression that they make through their choice of attire, so, too, can the crafting of the headline subtly shift the perception of the text that follows. By drawing attention to certain details or facts, a headline can affect what existing knowledge is activated in your head. By its choice of phrasing, a headline can influence your mindset as you read so that you later recall details that coincide with what you were expecting. For instance, the headline of this article I wrote—”A Gene That Makes You Need Less Sleep?”—is not inaccurate in any way. But it does likely prompt a focus on one specific part of the piece. If I had instead called it “Why We Need Eight Hours of Sleep,” people would remember it differently.
As a result of these shifts in perception, problems arise when a headline is ever so slightly misleading. “Air pollution now leading cause of lung cancer,” ran a headline last year in the U.K. paper Daily Express. The article, however, said no such thing, or, rather, not exactly. Instead, it reported that pollution was a leading “environmental” cause; other causes, like smoking, are still the main culprits. It is easy to understand a decision to run that sort of opening. Caveats don’t fit in single columns, and, once people are intrigued enough to read the story, they’ll get to the nuances just the same. But, as it turns out, reading the piece may not be enough to correct the headline’s misdirection.