This summary provides an overview of Barbara Fredrickson's contribution to the peak-end rule and duration neglect theory in 3 sentences: Barbara Fredrickson collaborated on seminal papers in 1993 that introduced the ideas of the peak-end rule and duration neglect to explain violations of rational decision making. Her 2000 paper critiqued previous research for focusing on "how" decisions were made rather than "why" based on meaning, and argued that peaks and ends carry subjective meaning that influences evaluations. Subsequent studies both confirmed and challenged aspects of Fredrickson's theory, providing a more nuanced understanding of how positive and negative experiences are integrated and recalled over time.

1. Peak-End Rule and Duration Neglect: An analysis of Barbara
Fredrickson’s contribution and related findings
John McCallie
The peak-end rule and notion of duration neglect has become a very robust tool for
examining violations to classical rational theory. Barbara Fredrickson served as one
of the more influential voices in this discovery, and therefore merits focus for her
contributions and influences on the topic. Hence, this paper is composed of two
parts: the first reviews Frederickson’s (2000) personal contribution to the
discussion on peak-end rule and duration neglect, and the second analyzes a
sampling of the empirical research on the topic since her article was published, and
the lack of expansion in areas she critiqued.
In 1993, Barbara Fredrickson collaborated with other researchers on two papers in which
they formulated the ideas of “peak-end rule” and “duration neglect” (Kahneman, Fredrickson,
Schrieber, & Redelmeier; Fredrickson and Kahneman). These two rules were used to explain
violations people make when making decisions that go against rational expectations. The peak-
end rule states that individuals, when evaluating past experiences, usually focus on the “peak”
and “end” moments of an interaction (Fredrickson 2000). To clarify, this means when a person is
in a situation, they do not evaluate the interaction in its entirety; rather, the subject will focus on
peak moments, the highs or lows, and how they felt when the moment ended. The basic
explanation for this is that most individuals cannot remember every moment they live through in
fine detail; therefore they must resort to heuristics and context clues in order to make
evaluations.

2. For example, a study was conducted in which a group of individuals were asked to
submerge their hands into cold water, inducing pain (Kahneman, Fredrickson, Schrieber, &
Redelmeier 1993). Participants were asked to submerge their hands in extremely cold water for
one minute, and then were asked to do the same test again, but for an additional 30 seconds, in
which the water’s temperature was slightly raised. The rational expectation is that individuals
would pick the shorter test, simply due to the total amount of discomfort being less (the water
temperature was only increased by one degree Celsius, meaning it was still a painful experience),
also known as “temporal monotonicity.” Yet, when asked to choose which trial they would want
to do for a third test, most chose the longer test, particularly those who reported a decrease in
discomfort after the temperature increase. Temporal monotonicity claims this is not possible. If
someone experiences pain for longer, even if the pain is less at the end than at the start, then their
total pain is higher than the shorter experience, and therefore they should always choose the short
test. The peak-end rule states this is not always the case, as individuals instead use markers, such
as peak moments and end moments, and evaluates the experience that way.
This study led to two conclusions: not only do people use peaks and ends of a
remembered experience to evaluate its desirability, but people also ignore the duration of the
event (duration neglect). This further tested in a more extreme manner by delaying the removal
of a colonoscopy device in some patients (Kahneman, Wakker, and Sarin 1997). After the
procedure was finished, instead of removing the tool, which is a painful experience, the scope
was left in for a minute, which is still painful, but much less than removal. This led to the curious
discovery that even though the pain was felt for a longer period of time, the procedures were
rated more desirable in evaluations at a later time. Fredrickson (2000) suggested that this finding
means “an intervention that improves the memory of a painful medical procedure---even if it

3. adds to the total experience of pain---might increase the patient’s willingness to undergo further
colonoscopies if needed” (p. 584). She also concludes that “[p]eoples global evaluations of their
past affective experiences, as well as their choices about the future, can often be well predicted
by a simply average of two moments: the most intense effective moment of that experience and
the affect experienced at the end” (p. 185).
Up to the publishing of Fredrickson’s critique in 2000, the peak-end rule and duration
neglect notion received more clarification by other researchers, such as how intensity of an
experience affects evaluation1 as well as duration not always being neglected2 (Fredrickson
2000, p. 586). But the main point of her article in 2000 is to ask why these things happen. Up to
that point, most of the studies cited have been trying to find out the “how” of violations to
temporal monotonicity, with little effort into explaining the behavior and factors that lead to
those choices. Thus, Fredrickson (2000) asks “[o]f all the moments people could select to
represent past affective experiences, why did they choose peaks and ends?” (p. 589). She argues
that there should be more empirical focus on meaning, to emphasize why peaks and ends hold
such weight in the decision makings of individuals. Therefore, the following section will be
focused on this part of Fredrickson’s (2000) article.
Evaluation by Meaning
Fredrickson splits her discussion of meaning into two parts: peaks and end carry
meaning, and emotions carry meaning. She criticizes that the “dominant view of time in many
Western cultures… is objective, absolute, and homogenous” creates the faulty conclusion that
1 (Hsee and Abelson 1991; Hsee, Salovey and Abelson 1994; Ariely 1998)
2 (Ariely 1998; Fredrickson and Kahneman 1993; Varey and Kahneman 1992)

4. humans all hold the same understanding of time (p. 589-590). Instead, people have subjective
views on time; they do not all start their day at 12:01 a.m. People evaluate their experience based
on subjectively relevant moments, and that is why moments like peaks or ends will have more
meaning. Meaning is gained not through time as is measured by clocks or other formal methods,
but is gained by the events themselves. This can also work in the opposite fashion, like when
saying “time flies when you’re having fun.” People who engage in an activity they enjoy will
feel as though the time spent was shorter than if they did a boring activity for the same amount of
objective time.
So if meaning is gained from the experience themselves, what relevance do peaks and
ends have? According to Fredrickson, peaks help convey “capacity requirements” or how much a
person can tolerate or engaged in an event. For example, experiencing a rather trying moment,
like a death or a broken limb, will tell an individual how much capacity they need in order to
handle reliving that experience, or if they can at all. Its importance in telling someone how much
effort they will need to handle the situation explains why the peak affect is so important in
evaluation. Fredrickson refers to it as a coping mechanism; if someone has their coping resources
depleted, they might experience high peak affects when engaging disturbing stimulus (p. 591).
When evaluating a past experience, or considering a future action, peaks will give an individual
valuable information about how to rate it and if they would perform it again.
On the other side of the spectrum, endings provide a different importance. Fredrickson
uses “ends justify the means” as to explain the personal importance of end affects, in which
individuals may remember the overall experience in a more positive light if the end result makes
the entire experience worth it (p. 592). She cites endings as being the main aspect of experience
by humans (see Spiegel 1998), and this is what brings about the importance placed on the end

5. affect (p. 592). Also, endings make clear the peak moments of an experience, and therefore show
not only that you survived the experience, but now you can use it to discover your personal
capacity. This supposedly explains why people seek thrill-seeking activities; by surviving them,
they can discover limits about themselves. Frederickson concludes that both peaks and ends give
relevant information about the self, hence why they seem so important in decision making.
Besides the peak and end meanings, Fredrickson also looked at emotion as creating
meaning which will affect decisions and evaluations. In fact, she specifically criticizes how the
research up to this point (that she discussed) lacked virtually any focus on emotions and how
they affect decisions: “Affect, the measures used would imply, varies along a single bipolar
‘good-bad’ dimension” (p. 594). Measurement is seen as a crux, keeping researchers from
accurately rating a person’s feelings on something, or imposing a scale that does not truly reflect
the mindset of an individual. It also tends to ignore the multitude of feelings experience by
someone. While an subject participates in some sort of phenomena, their emotions are not
limited to a simple good or bad scale, but that scale is made up of a myriad of different emotions.
A classical researcher may see an experience as unavoidable because it will cause pain, and
therefore no individual should seek it out. But it also ignores other levels of affects that might
come into play, split into different levels. Fredrickson refers to these levels as high meaning and
low meaning affects, with things like love and interest being high meaning positive affects, and
anxiety and disgust as low meaning negative affects (p. 595).
In context of decision making, this helps explain why people would prefer to do
something painful or disgusting (negative), even though this might break rational expectations.
Fredrickson refers to horror movie-goers as a clear representation of this; the subsequent
enjoyment they receive from going to see the movie overrides the initial fear they have, leading

6. to them describing the overall experience as enjoyable and will seek it out again (p. 596). Her
argument can also be used to fortify the peak and end discussion earlier, in that people may
experience peak fears, which relay information about their tolerance for such situations, but they
also enjoy the feeling of proving their bravery, even if only to themselves. Their desire for a
higher meaning positive affect such as courage might override their anxiety, which might be seen
as a low meaning negative affect.
Hence Fredrickson’s critique of bipolar measures of meaning: if subject A enjoys the
rush from horror movies, more so than the dislikes the fear from it, they will rate the experience
as “good”, while subject B will rate it as “bad” because they do not enjoy the rush as much as
they dislike the fear. Their peaks and ends convey different meanings to themselves, leading to
different results on the bipolar evaluation. Furthermore, while Fredrickson does not explicitly
state this, the bipolar measurement tool is also based on the researcher’s decision. They assume
that horror movies are bad (they are scary and cause fear, which is assumed to cause universal
negative reactions), but completely ignores any other effect the movie might have that can lead
to a “good” evaluation. It also ignores the saliency of those affects, since not all individuals
experience the situation the same way. A peak moment will not be the same for subject A and B,
and the ends will mean different things to them: relief for subject B, but pride for subject A.
This leads to Fredrickson finding a fundamental flaw with how happiness and choices are
analyzed: the methodology gives little attention to the meaning associated with the affects. The
measurements for happiness and how meanings are scaled against each other provide issues for
evaluating by meaning, with most only looking at moments, and not remedying situations where
two different levels of meaning are measure equally (does a day with a child that gives +7 and is
described as love mean less than a tuna steak measured +10 described as pleasure?) (p. 601).

7. While this seems like an obvious error, there is little that had been done to address this issue,
mainly due to focus on evaluation by moments rather than meaning. But has subsequent research
since her article discovered anything new?
Subsequent Empirical Findings
In 2004, a study was conducted using two separate experiments to evaluate the effects of
mixing positive and negative affects together and seeing if starting and ending on different notes
will change the overall evaluation of the experience (Olsen and Pracejus). Each experiment
tested the effects of mood while listening to a radio ad, in which four versions were offered
(positive only, negative only, negative-positive, and positive-negative). Each segment had
matching verbal and audio cues, so that the music being played matched the tone of the
announcer. This study found that changing when information was presented, and in what way,
changed the overall evaluation of the ad. Interestingly, they found significant mood increases by
following negative affects with positive affects, as compared with an ad with just positive
affects. Following positive affects with negative ones were not significantly different than only
negative ads.
What also separates this study from others was their attention to ensuring the affects were
generally interpreted the same by all individuals, in order to avoid testing error in which
statements or types of music were misidentified with the wrong meaning. This differs
particularly from research cited by Fredrickson, who criticized that meaning interpreted from
individuals was largely ignored. It also considered multiple types of stimuli and the meanings
they convey (music versus spoken word) to evaluate the difference in responses they generate. In
their words, “this study presents the first investigation into the integration of oppositely valenced

8. affective stimuli” (p. 383). Their findings also reiterate the importance of different levels and
types of meanings as they pertain to the message, without changing the overall impact.
Therefore, assuming that negative and positive reactions will operate in the same way isn’t
always true, and careful attention should be paid when studying their effects.
Another study sought to determine if autobiographical events, in which persons keep
track of their happiness throughout, still obey the peak-end rule (Kemp, Burt and Furneaux
2008). The theory behind this was that few studies up to this point had looked at long-term
events and focused on short-term unpleasant ones, mainly due to practicality (p. 132). This study
also aimed to address the difference between day to day evaluations and recall evaluations at a
later date, to see if people remembered experiences differently than they actually occured
(signifying bias towards some events). Furthermore, there was an intent to see if the “peaks” held
the dominate effect in recollection, or if “troughs” also came into effect when remembering past
experiences. In other words, do negative events drive down evaluations of overall positive
events, or is the recollection one sided?
The results both confirmed and refuted Fredrickson’s findings and hypotheses. First of
all, this study reiterated that duration of experiences did not change overall levels of happiness,
so longer vacations were as enjoyable as shorter ones. Also, the data found that people do tend to
reconstruct events rather than remember them correctly as the memory gets older. Overall, the
study supports Kahneman and Fredrickson’s (1993) finding that memories consists of averaged
“stills”, rather than continuous recollections, mainly due to the limitations of the mind. This was
further supported by the fact that people had a hard time graphing their happiness day-by-day
after the vacation was over. Generally, people made guesses about how they felt at certain

9. moments rather than remembering exactly how they felt at a specific point, with accuracy
decreasing as time went on.
The study also found the peak-end rule to not be a perfect heuristic tool for individuals
when recalling memories. Rather, “overall happiness seems to be better predicted by end
happiness than by peak or trough happiness, and the comparative failure of the peak-end rule
appears to stem more from the peak than from the end” (p. 137). In fact, the peaks and troughs
were not any more well-remembered than other moments, and the ends were more often used to
recall overall happiness. The perceived intensity of these peaks decreased as time went on,
leading the researchers to suggest that, while peak and end experiences may be used in
evaluation, other candidates like beginning, unusual, and relevant memories might be more
likely recalled. These finding challenges the supremacy of the peak-end rule, but it does not
disprove it. In fact, it supports Fredrickson’s (2000) argument that other factors may come into
play when evaluating experiences. That, or the peak-end rule is too restrictive in what qualifies
as a “peak.”
Do, Rupert, and Wolford (2008) also attempted to determine how the peak-end rule
comes into play concerning positive experiences, using similar methods used in the ice-water
experiment. In one experiment, a group of participants were asked to choose a reward from two
sets of DVDS, with one set being highly rated movies (A) and the other being decently rated, but
not as high as the first set (b). Each person picked two movies from one or two lists. Five
possible combinations of movies were offered: Only offered A, only offered B, pick from A then
pick from B in a separate email, pick from B then pick from A in a separate email, and pick from
A then pick from A in a separate email. A second experiment did a similar test, except with

10. candy during trick-or-treating by children on Halloween night (only this time, there was no B
then A choice).
The results they obtained fell in line with previous findings cited in Fredrickson (2000).
Subjects rated their overall happiness higher when picking the A group second, than if they
picked the B group second. This reiterates the importance of ordering when offering gifts, or
otherwise seeking pleasurable experiences, and seems to be something inherent regardless of age
(both the adults with the DVDs and the kids with the candy acted the same behaviorally). While
this doesn’t add to the “why” Fredrickson is asking for, it is still important in that it upholds the
validity of her argument that the peak-end rule has a lot of influence in situational analysis, even
with an immediate recall. This competes with the previous study, meaning more intense research
is needed to fully clarify its validity in all cases.
A study conducted by Winterich and Haws (2011) set out to find if different types of
positive states leads to different consumption habits (particularly food). This addresses
Fredrickson’s (2000) criticism of the lack of research concerning different types of emotions and
meanings, which may lead to conflicting answers. This particular test seeks to see if different
temporal focuses will lead to different eating behaviors, such as the increased consumption of
unhealthy food (i.e. do emotions like hopefulness, which is future-oriented, lead to different
choices than emotions like happiness, which is present-oriented, even though they are both
positive?). The basis of this study is predicated on the past focus concerning “valence-based
mood states”, such as negative vs. positive, rather than specific emotions, as highlighted above.
Their findings suggest that not only do different emotions in the same positive valence
affect self-control (and possibly other behaviors) in unique ways, future-focused positive
emotions seem to be more impactful on self-control than other temporally focused versions. This

11. also supports Fredrickson’s hypothesis concerning differing meaning affects, albeit this one adds
a temporal element, which allows for more diversity in explaining behavior. In effect, not only
does their conclusion imply that positive meanings and emotions can improve self-control, but
it’s the temporal qualification of the emotion that really changes the behavior of the individual.
This challenges studies that only focus on the “good/bad”, bilateral measurement of experiences,
rather than a more nuanced, inter-valence examination. Such consideration should, theoretically,
better explain how people make decisions and evaluate phenomena.
Up to this point, little attention has been given specifically to duration neglect, partly
because Fredrickson’s focus in her 2000 article is on the peak-end rule. But the two are very
closely related, and Zhao and Tsai’s (2011) study offers keen insight on the role of duration in
personal evaluation. They tested how people’s evaluations would change if the subject had
knowledge of the duration of the test. First, they found that there was an additive effect to
intensity when a subject had duration knowledge, regardless if the duration conformed to
expectations or not. This means that a positive experience was more enjoyable with duration
knowledge, and negative experiences were more unenjoyable as well. This held regardless of
length of the experience or if actual duration violated expectation of length. However, the
researchers caution that the tested experiences were relatively mild, and so this might not be the
case for more extreme experiences (like childbirth).
They also found a reverse effect when those who had knowledge of duration focused on
the ending of the experience. This was attributed to a focus or attention effect; people thought
more about the end of the test than the test itself, and the overall impact was dulled. Yet there
was also the conclusion that people who knew exactly when the test ended paid more attention as
the end grew nearer, which increased the intensity of the experience. This gives slightly

12. contradictory results, because they are implying that, on average, the intensity drops, but it gains
an exponential increase as the ending nears. This gives no insight into which has a stronger
effect, or which is more likely to occur, so more research could possibly alleviate this.
Regardless of that contradiction, the study does still add a new, unexamined layer to duration and
its properties, and that knowledge may give power to duration on experience.
Conclusionand Remarks
Barbara Fredrickson, who helped initiate the discussion on peak-end effects and duration
neglect, alongside Kahneman and colleagues, seems to be left wanting for more adequate reasons
for why such rules exist. Her critique revolves around a general lack of understanding the
mechanisms of hedonistic heuristics, and infers that there must be other influences at play,
mainly focusing around meaning. For Fredrickson, meaning contains a lot of the power behind
why individuals commit seemingly irrational actions, but we have lacked the methodological
tools and interest in discovering these nuanced difference. Despite that, she hypothesizes that the
reason the peak-end rule, and in relation to that, duration neglect, hold so much influence in the
evaluation of experienced memories is due to the meaning those two moments hold. Peaks
convey a sense of personal capacity, giving an individual information about what kind of
situations they can endure, and how much effort or willpower or emotion they need in order to
survive or engage in the experience again. In relation, endings signify closure and goal-
accomplishment, and allow an individual to realize the peaks and use them to evaluate their
overall feelings about the experience, and whether or not they think the means were worth the
result. How this is done, and to what extent this rule holds, though, is something Fredrickson
feels is not adequately answered, and would welcome attempts to clarify those relations.

13. Since her article, various studies have been performed either to support or challenge the
peak-end rule and duration neglect, or expand upon the literature and discover new dynamics
previously untested. This paper is not nearly a full collection of the research following
Fredrickson’s article, as the peak-end rule in particular has garnered a lot of academic interest.
That said, the discussed research does highlight some of the important discoveries that have been
made since her analysis.
First, there is still some debate as to whether or not the peak-end rule is descriptive tool
for explaining how people evaluate past experiences. For example, Kemp, Burt and Furneaux
(2008) claimed that while the peak-end rule can sometimes explain the methods used by
individuals, when compared to moment-by-moment evaluations, other tools seem to be more
relevant when remembering the past. Do, Rupert, and Wolford’s (2008) findings, on the other
hand, seem to support the original theory, and apply it to positive experiences rather than
negative, which is more commonly analyzed. It is unknown if there are other possible effects,
such increased subject attention given to mood states in the first study, that might influence the
findings. Regardless, the rule still seems to hold significant power in the literature.
Second, a couple studies have sought out more refined answers to how time comes into
play concerning behavior and recollection. Winterich and Haws (2011) found that future-
oriented positive states are better at keeping someone from eating unhealthy, so time plays some
effect in decisions, just not in a way considered in-depth previously. This is related to
Fredrickson’s issue with unilateral or bilateral scales, that usually only look at something in a
valence manner (“good vs. bad”) or that fail to take in account other emotions that might affect
decisions (“I want to do things I like, but I want to avoid shame more”). Zhao and Tsai (2011)
found that duration does have an effect, not due to its length, but knowledge of length, which still

14. supports duration neglect. They discovered that those who had expectations or knew the duration
of an experience increased the intensity of the experience positively and negatively.
Finally, Olsen and Pracejus (2004) conducted a similar study which is relatable to the
previous studies. They showed that not only does ordering affect how something is perceived (a
well-researched phenomena, also addressed by Do, Rupert, and Wolford), but that different types
of the same affect will change the intensity and meaning associated with an experience (similar
to the findings by Winterich and Haws). This gives support to Fredrickson’s argument that not
all affects are the same, and individuals will associate different relevance and intensities to
affects that resonate more with their personal desires or behaviors.
While many of these findings and studies reveal a plethora of information that was either
ignored or unknown in the past, it is still not enough. There are too many unknowns about the
reasons why people behave the way they do, especially in an empirical sense, and there still
exists a deficiency in adequate ways to measure these hidden meanings. On top of that, while
more research exists concerning the peak-end rule, much of it still focuses on the moments rather
than expanding on the meanings (again, probably due to the lack of consistent measurements in
the discipline).
As Fredrickson said, the way to answer these questions may be daunting and taxing, and
the methods currently available lacking in descriptive power, but if we don’t pursue those
answers we may never really understand why people behave the way they do in a meaningful
way. But that is not said to discredit what work has been done in the last couple decades. I would
argue that due to work like Fredrickson, Kahneman, and all the researchers cited above, we have
a better understanding as to how people make decisions and make consumption choices. Without

15. them, we would still be stuck with the classic rational assumptions that would leave virtually
every human decision irrational or uninformed.
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