Maria Konnikova, 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.