Early yea-saying errors on surveys stem partly from shallow processing.

Evidence

It appeared therefore that giving subjects a second chance at early items, especially contraits, helped them overcome response set tendencies. Perhaps they better understood what the statements meant after answering the whole test (Tourangeau and Rasinski, 1988), or perhaps the intervening items— especially the contraits—caused subjects to “process deeper” and more carefully (Krosnick, 1991). — Bob Altemeyer, The Authoritarian Specter, 835