ABSTRACT
This chapter aims to explain the crucial role of theory in developing useful scientific methodologies for research on eyewitness testimony and, ultimately, in improving legal policies and practices. We discuss a series of effects that are manifested in the real world and that surprise our intuitions. Laboratory research has shown that witnesses can assert the reality of events that never happened with great confidence; that this effect can be reversed by strengthening one type of memory that is different from another type; that memory is not one thing and that one type of memory does not forget easily and the other one does; that false memory often draws on ordinary processes of meaning-making that are rife in the real world; that falsifying processes of memory are suppressed close to an event but emerge unopposed later, and contribute to inconsistencies in memory reports that seem like lies but are not lies; that “pristine” lineups under immediate testing conditions are effective to the degree that they tap one type of memory rather than another; that confidence in testimony is affected by which type of memory is accessed at the time; that talking and remembering can interfere with one another in surprising ways explained by fuzzy-trace theory (FTT); that ordinary people will remember the suspect being the perpetrator and the suspect not being the perpetrator at the same time, and not be lying or guessing; and, finally, that age affects the types of memories that witnesses tap in ways predicted by theory.
