Current Directions in Psychological
Science
20(5) 312­–315
© The Author(s) 2011
Reprints and permission:
sagepub.com/journalsPermissions.nav
DOI: 10.1177/0963721411416571
http://cdps.sagepub.com
False memories, or memories for part or all of an experience
that did not actually occur, are one consequence of a powerful
and adaptive memory system that is reconstructive. Although
much of today’s research on memory illusions focuses on their
negative consequences (e.g., such as those seen in the forensic
arena), some recent research has convincingly demonstrated
that false memories can have positive consequences. These
more positive consequences occur not only in terms of other
cognitive processes (reasoning, problem solving; e.g., Howe,
Garner, Charlesworth, & Knott, 2011) but also influence future
behavior (Chen, Zeltzer, Craske, & Katz, 1999), as well as
guide planning for future actions, perhaps the quintessential
adaptive function associated with memory (e.g., Atance &
O’Neill, 2005; Hassabis & Maguire, 2007). In this article, the
adaptive nature of memory, both true and false, is articulated
using a variety of recent studies including those showing that
processing information for its relevance to survival can lead to
improvements in remembering, both in adults (for a review,
see Nairne, 2010) and in children (Otgaar & Smeets, 2010).
Surprisingly, such processing also leads to increased falsememory
rates, resulting in a net decrease in overall accuracy
(Howe & Derbish, 2010). It is this latter discovery that has led
to a new, adaptive perspective on memory illusions, one that
parallels other discoveries concerning the adaptive value of
perceptual and cognitive illusions more generally (McKay &
Dennett, 2009).
Adaptive Memory
It is, perhaps, self-evident that memory is one adaptive system
that has emerged out of a variety of evolutionary pressures. It
is not known exactly when, or under what adaptive pressures,
individual memory became an essential evolutionary adaptation.
Speculation suggests that it may have emerged some 500
million years ago (Ginsburg & Jablonka, 2010). This “Cambrian
explosion” and its attendant advance in memory marked
a critical change in the number and variety of fitness-relevant
behaviors available to organisms. These advances included
memory for locations where survival-essential resources (e.g.,
food and water) could be found, shaped the manner in which
organisms searched for mating partners, and helped them recognize
and avoid predators (Ginsburg & Jablonka, 2010).
Memory is essential to many survival-relevant behaviors,
especially learning associations between significant objects
(e.g., predators) and signs of their presence (e.g., odors, rustling
grass). The evolution of memory, particularly associative
memory in which past experiences can be retained, opened up
hitherto unseen mechanisms for adaptive change, including
the ability to mentally simulate possible future states when
deciding the best course of action given multiple alternatives
(Hassabis & Maguire, 2007).
Research has shown that the neural mechanisms underlying
recall of past episodes also underlie imagining future behaviors,
although the source of this similarity remains unclear
(Hassabis & Maguire, 2007). Recent evidence has shown the
important role that dopamine plays in remembering previous
experiences, linking current information to those memories,
Corresponding Author:
Mark L. Howe, Ph.D., Lancaster University, Lancaster, LA1 4YF, UK
E-mail: mark.howe@lancaster.ac.uk
The Adaptive Nature of Memory
and Its Illusions
Mark L. Howe
Lancaster University
Abstract
In this article I discuss how false memories do not always have to be associated with negative outcomes. Indeed, under
some circumstances, memory illusions, like other illusions more generally, can have positive consequences. I discuss these
consequences in the context of the adaptive function of memory, including how false memories can have fitness-relevant
benefits for subsequent behavior and problem solving. My hope is that this article changes how illusions are conceptualized,
especially those arising from memory.Rather than being a“demon” that vexes our theories of memory,illusions can be thought
of as sometimes having positive consequences much in the same way as many of the other outputs of a very powerful, adaptive
memory system.
Keywords
adaptive memory, memory illusions, false beliefs
Adaptive Memory Illusions	 313
and utilizing these associations in the service of future, adaptive
behaviors. That is, “when individuals encounter new
information that evokes old associations, this associative novelty
can promote not only preferential encoding but also the
organization of memory to facilitate its later use—processes
that could be catalyzed by dopamine” (Shohamy & Adcock,
2010, p. 468). Thus, there is compelling behavioral and neuroscientific
evidence supporting the idea that memory has been
shaped by evolution with adaptation in mind.
Additional behavioral evidence comes from two distinct
lines of research concerning how evolution may have affected
memory. First, memory may have become specialized to perform
very particular functions, including recognition of trustworthiness,
which may enhance survival by helping individuals
avoid others who are deceptive (e.g., Mehl & Buchner, 2008).
Others suggest that memory was shaped by gender differences
in the division of labor, in which spatial-memory requirements
were different for men who hunted mobile prey than for
women who gathered food from fixed and immobile locations
(Pacheco-Cobos, Rosetti, Cuatianquiz, & Hudson, 2010).
Second, research has examined whether memory is specialized
to retain fitness-relevant survival information (Nairne,
2010). Here, participants are given an ancestrally relevant
(e.g., surviving in the grasslands) or irrelevant (e.g., surviving
in a city) scenario and are asked to evaluate the importance of
a list of words in the context of these environments. Concepts
rated for ancestrally relevant survival are remembered better
on a surprise memory test.
Although there is disagreement concerning the importance
of an evolutionary interpretation of these findings, another
problem has emerged: Not only are there more true memories
generated in this adaptive-memory procedure, but also more
false memories. Using lists of highly associated concepts
that were survival relevant, negatively valenced, or neutral,
both true and false memories were more abundant when items
were rated for survival. Independent of processing, survivalrelevant
concepts also evinced higher rates of true and false
recollection (Howe & Derbish, 2010).
Together, these results raise several concerns, not the least
of which is that “adaptive memory” results in reduced, not
enhanced, accuracy. Because false memories increase at a rate
commensurate with true memories for survival materials and
survival processing, overall recollective accuracy necessarily
decreases relative to other types of materials and processing.
Therefore, we can ask why correlated increases in both true
and false memories are adaptive and, moreover, what possible
adaptive significance there would be for constructing memories
that are either entirely, or even just partially, false. It is
important to answer these questions because, depending on
their context, false memories may have negative consequences
(e.g., the conviction of innocent people) rather than positive
ones (e.g., evading predators). Before getting to this, I turn to
a more general problem—namely, what is the adaptive value
of illusions more generally?
Do Some Illusions Have Adaptive
Consequences?
Illusions of various origins occur more frequently than we
think. Indeed, research in the visual sciences has shown that
much of what we “see” is actually a type of “intelligent” hallucination
(Gregory, 1968). In fact, perceptual illusions are
critical to adaptation, because in many natural environments,
the type and amount of sensory information available can vary
over time and across space. For example, “it is important to be
able to perceive surfaces independently of their varying light
intensity (and vice versa) in order to forage or predate successfully”
(Corney & Lotto, 2007, p. 1790). That illusions occur is
a simple consequence of the constructive nature of perception;
“every instrument has measurement errors and the human
visual system is no exception. So every percept will have an
error associated with it, be it large or small” (Corney & Lotto,
2007, p. 1797).
Magicians have long exploited frailties of our visual system
by creating optical illusions involving mirrors, lighting, and
variations in object perspective. Cognitive illusions also
abound and are similarly manipulated by magicians who use
sleight of hand. The key here is to create a false action (e.g.,
pretending to move an object from one hand to another) that
makes the audience think they are seeing a real action. Indeed,
audiences frequently report seeing and remembering the “real”
event even though it never happened (for a review, see Kuhn,
Amlani, & Rensink, 2008). Although these illusions are not
necessarily adaptive (unless you are attempting to survive by
being a magician), they are based on principles derived from
basic mechanisms that are quite adaptive.
Although the systems that create illusions are themselves
shaped by evolution, whether the illusions themselves are
adaptive depends on the nature of the illusion and the context
in which it occurs. Indeed, as already noted in the case of
memory illusions, not all errors have adaptive consequences.
Although not all cognitive errors are adaptive (e.g., the Cotard
delusion, in which an individual comes to believe he or she is
dead), there are many that have fitness relevance (McKay &
Dennett, 2009). For example, positive yet illusion-like selfappraisals
can lead to a sense of confidence, leading to better
chances of success in future tasks. Moreover, illusion-like
beliefs can affect health. For example, individuals may believe
that the medicine they are taking can cure what is ailing them,
and then it does, despite the fact that the “medicine” is a
placebo.
Do Some Memory Illusions Have
Adaptive Consequences?
Little doubt exists that memory is a powerful and flexible system
that is essential to an organism’s ability to adapt and survive.
Representational flexibility is key to an organism’s
ability to restructure and update what is in memory, a critical
314		 Howe
feature of memory that is linked to an organism’s survival. The
processes involved in that flexibility include the combining,
rewriting, and blending of incoming information with information
already stored in memory. However, because memory
is so malleable, remembering is a process that, like the other
perceptual and cognitive processes, is prone to error and,
under some circumstances, can go inexorably wrong.
Just how wrong can remembering be? At one end of the
spectrum, we may make memory errors concerning less consequential
aspects of our experiences, perhaps confusing two
similar experiences (e.g., whether we wore a black or blue suit
to work yesterday) or by inferring that events occurred because
they are consistent with world knowledge (e.g., inferring, but
not explicitly remembering, that we locked the door before
leaving for work). At the other end of the spectrum, people
falsely remember entire events occurring when no such event
has taken place (e.g., being abducted by a UFO; Spanos, 1996).
Although we know a considerable amount about the
“darker” side of memory illusions (as when people falsely
remember being sexually abused), we know much less about
the positive and potentially adaptive functions associated with
memory illusions. Recently, we (Howe & Derbish, 2010;
Howe et al., 2011) have argued that false memories, like false
beliefs, can (depending on their content and context) have an
adaptive consequence. For example, one adaptive value of
false autobiographical recollection is the tendency toward positive
biasing of one’s past self. These “misrememberings”
involve false memories about the self rather than the event, and
they allow revision of the past that facilitates self-enhancement,
permits a more positive self-evaluation of one’s current self,
and helps maintain effective social relations (Ross & Wilson,
2003). This positivity has also been linked to enhanced emotional
regulation (Mather & Cartensen, 2005) that, in turn, has
been interpreted as being an extremely adaptive function of
memory—or more accurately, of false remembering (Newman
& Lindsay, 2009). This is because such recollections can
directly benefit one’s current self-image and influence future
behaviors and motivations. Indeed, because many functions of
autobiographical memory are arguably social, false memories
of our past may (a) be quite adaptive inasmuch as they serve to
enhance social relationships and (b) serve to enhance intimacy
in relationships, a goal more important than keeping an accurate
record of one’s past.
False memories may have other adaptive uses, including
aiding the solution to problems in a survival-related context,
something that may be a crucial evolutionary trait. An increase
in false memories for survival information may not necessarily
be maladaptive if they can prime solutions to complex
problems in a manner similar to true memories. As Howe and
Derbish (2010) pointed out, that the byproduct of memory
activation can be a false recollection may be a small price to
pay if such false memories, like true memories, can aid the
solution of more complex, survival-relevant problems.
As a first approximation to the study of false memories and
problem solving, Howe et al. (2011) presented children and
adults with lists of associated words that gave rise to false
memories. These false memories were also the solution to
compound remote-associate problems—that is, problems that
were presented after participants studied the word lists. For
those participants who generated a false memory following
list presentation, subsequent problem solving was not only
easier (higher success rates) but was also faster. Thus, false
memories generated by participants primed solutions in a later
problem-solving task, much in the same way true memories
prime solutions on other, related tasks.
Conclusions and Future Directions
Perception, cognition, and memory are all powerful adaptive
systems that are prone to errors (illusions) given their (re)constructive
nature. Illusions are not always detrimental, and
many have more positive, fitness-relevant consequences.
Indeed, false memories not only allow us to (mis)remember a
past that facilitates the present (e.g., maintain intimate relationships)
but also helps us predict the future (e.g., avoid
predators).
As intriguing as these ideas may be, it is only by testing
specific experimental predictions about the fitness-relevant
consequences of remembering that our understanding of the
adaptive function of memory (both true and false) will grow
(see Nairne, 2010). Indeed, some researchers have tested exact
predictions concerning the adaptive value of false remembering,
including specific behavioral consequences that are linked
to developing false memories. For example, children who
came to falsely remember prior lumbar punctures as less painful
than they actually were experienced less distress during
subsequent lumbar punctures (Chen et al., 1999). Therefore,
reframing memories of the past can have fitness-relevant consequences
that include making life-saving treatments not only
more bearable but also more likely to continue. Additional
research might focus on how episodic-memory errors (and
accuracies) contribute to the emergence and development of
future thinking (Atance & O’Neill, 2005), including how
memory for experiences and solutions to past problems are
used to alter future behaviors and solutions to new problems
(Suddendorf, Nielson, & von Gehlen, 2011).
Although considerable research remains ahead of us, false
memories can have positive consequences, not just negative
ones. Determining the adaptive benefits of false memories, like
those for true memories, requires innovative experimental
design, the measurement of behavioral changes, and the assessment
of the fitness-relevant consequences of such memory illusions,
immediately as well as in the future. In this article, I have
attempted to demonstrate that false—like accurate—remembering
does influence current as well as later behaviors and may
even influence the construction of plans for the future. This is
critical because it illustrates the powerful influence memory has
on behavior, regardless of memory’s truth value. Whether a
behavior’s consequences are positive (e.g., potentially increasing
the likelihood of life-saving medical treatment) or negative
Adaptive Memory Illusions	 315
(e.g., false accusations of sexual abuse leading to imprisonment
of innocent people) depends on both the content of those memories
as well as the context in which that remembering occurs.
The point here is simply that while we know much about the
negative consequences of memory illusions, future research
should also focus on the positive consequences of misremembering
our past.
Recommended Reading
Howe, M.L. (2011). The nature of early memory: An adaptive theory
of the genesis and development of memory. New York, NY:
Oxford University Press. Outlines an adaptive theory of memory
and its development, including false memories.
Kuhn, G., Amlani, A.A., & Rensink, R.A. (2008). (See References).
Goes into greater depth concerning how magicians exploit the
frailties of the human visual system to create illusions.
McKay, R.T., & Dennett, D.C. (2009). (See References). Goes into
greater depth concerning the nature of cognitive illusions, or false
beliefs.
Paivio, A. (2007). Mind and its evolution: A dual coding approach.
Mahwah, NJ: Erlbaum. Provides a more detailed analysis of the
evolution of cognitive processes.
Roediger, H.L., III. (1996). Memory illusions. Journal of Memory
and Language, 35, 76–100. Provides an in-depth look at memory
illusions and grounds the study of these illusions in terms of illusions
commonly found in perception.
Acknowledgments
The author thanks two anonymous reviewers and Henry Roediger for
their very thoughtful comments on an earlier draft of this article.
Declaration of Conflicting Interests
The author declared no potential conflicts of interest with respect to
the research, authorship, and/or publication of this article.
References
Atance, C.M., & O’Neill, D.K. (2005). The emergence of episodic
future thinking in humans. Learning and Motivation, 36,
126–144.
Chen, E., Zeltzer, L.K., Craske, M.G., & Katz, E.R. (1999). Alteration
of memory in the reduction of children’s distress during
repeated aversive medical procedures. Journal of Consulting and
Clinical Psychology, 67, 481–490.
Corney, D., & Lotto, R.B. (2007). What are lightness illusions and why
do we see them? PLoS Computational Biology, 3, 1790–1800.
Ginsburg, S., & Jablonka, E. (2010). The evolution of associative
learning: A factor in the Cambrian explosion. Journal of Theoretical
Biology, 266, 11–20.
Gregory, R.L. (1968). Perceptual illusions and brain models. Proceedings
of the Royal Society of London: B. Biological Sciences,
171, 179–296.
Hassabis, D., & Maguire, E.A. (2007). Deconstructing episodic memory
with construction. Trends in Cognitive Sciences, 11, 299–306.
Howe, M.L., & Derbish, M.H. (2010). On the susceptibility of adaptive
memory to false memory illusions. Cognition, 115, 252–267.
Howe, M.L., Garner, S.R., Charlesworth, M., & Knott, L. (2011).
A brighter side to false memory illusions: False memories can
prime children’s and adults’insight-based problem solving. Journal
of Experimental Child Psychology, 108, 383–393.
Kuhn, G., Amlani, A.A., & Rensink, R.A. (2008). Towards a science
of magic. Trends in Cognitive Sciences, 12, 349–354.
Mather, M., & Cartensen, L.L. (2005). Aging and motivated cognition:
The positive effect in attention and memory. Trends in Cognitive
Sciences, 9, 496–502.
McKay, R.T., & Dennett, D.C. (2009). The evolution of misbelief.
Behavioral and Brain Sciences, 32, 493–561.
Mehl, B., & Buchner, A. (2008). No enhanced memory for faces of
cheaters. Evolution and Human Behavior, 29, 35–41.
Nairne, J.S. (2010). Adaptive memory: Evolutionary constraints on
remembering. Psychology of Learning and Motivation, 53, 1–32.
Newman, E.J., & Lindsay, D.S. (2009). False memories: What the
hell are they for? Applied Cognitive Psychology, 23, 1105–1121.
Otgaar, H., & Smeets, T. (2010). Adaptive memory: Survival processing
increases both true and false memory in adults and children.
Journal of Experimental Psychology: Learning, Memory,
and Cognition, 36, 1010–1016.
Pacheco-Cobos, L., Rosetti, M., Cuatianquiz, C., & Hudson, R.
(2010). Sex differences in mushroom gathering: Men expend
more energy to obtain equivalent benefits. Evolution and Human
Behavior, 31, 289–297.
Ross, M., & Wilson, A.E. (2003). Autobiographical memory and conceptions
of the self: Getting better all the time. Current Directions
in Psychological Science, 12, 66–69.
Shohamy, D., & Adcock, R.A. (2010). Dopamine and adaptive memory.
Trends in Cognitive Sciences, 14, 464–472.
Spanos, N.P. (1996). Multiple identities and false memories: A sociocognitive
perspective. Washington, DC: American Psychological
Association.
Suddendorf, T., Nielson, M., & von Gehlen, R. (2011). Children’s
capacity to remember a novel problem and to secure its future
solution. Developmental Science, 14, 26–33.