knew-it-all-along effect

1854 People often have difficulty retrospectively determining the level of knowledge they had prior to acquiring new knowledge (e.g., Fischhoff, 1975; Hasher, Attig, & Alba, 1981; Wood, 1978). Fischhoff (1977) coined the phrase knew-it-all-along (KIA) effect to describe this phenomenon, although it also is commonly referred to as hindsight bias. In a typical KIA paradigm, participants respond to a set of general knowledge questions, after which they are told the correct answers to a portion of the questions; the participants are later asked to respond to the questions with the same answers that they had given prior to being exposed to the feedback. The KIA effect occurs when participants give the correct answers to significantly more feedback questions than nonfeedback questions, indicating an overestimation of their prior knowledge (Fischhoff, 1977). Hindsight bias has garnered a large volume of research since the mid-1970s, and it has been demonstrated in a wide variety of settings, such as relationship satisfaction (Halford & Griffith, 2002), forensic psychology (Williams, 1992), gustatory judgments (Pohl, Schwarz, Sczesny, & Stahlberg, 2003), and sporting events (Bonds-Raacke, Fryer, Nicks, & Durr, 2001). However, the KIA effect would be a good deal less interesting, and have far weaker practical implications, if it turned out that whenever participants demonstrate the effect they report that they are merely guessing or inferring their prior responses (cf. the eyewitness misinformation effect; e.g., Lindsay & Johnson, 1989; Zaragoza & Koshmider, 1989). If, in contrast, participants often report illusory beliefs or memories of having “known it all along,” many interesting questions follow as to the mechanisms underlying those illusions. The present work takes some initial steps toward exploring conditions under which such illusions do versus do not arise. There are different types of hindsight bias (i.e., based on how the phenomenon is measured), but our interest focuses on the KIA effect that arises with comparisons of foresight and hindsight judgments within subjects (commonly referred to as memory designs; see, e.g., Dehn & Erdfelder, 1998; Fischhoff & Beyth, 1975; Hasher et al., 1981). In such studies, as in the example given above, each participant completes the same set of judgments twice, once before and once after exposure to the correct answers. The participants are asked to complete the latter judgments with exactly the same answers as those that they had given prior to receiving the feedback. Fischhoff (1975, 1977; Fischhoff & Beyth, 1975) proposed that the KIA effect results from an automatic assimilation of the correct feedback with preexisting knowledge (i.e., a memory impairment account; cf. Loftus, 1979). A feeling of KIA occurs because the assimilation of new information with prior knowledge eradicates the original knowledge state, making it impossible for an individual to “I remember/know/guess that I knew it all along!”: Subjective experience versus objective measures of the knew-it-all-along effect