Power and Time Predictions 1
In Press: Journal of Experimental Social Psychology
How Long Will It Take?
Power Biases Time Predictions
University of Kent
University College London
Keywords: Power, control, time, planning fallacy, forecasting
Please address correspondence to Mario Weick, Department of Psychology,
University of Kent at Canterbury, Canterbury, Kent, CT2 7NP, UK. Email:
Power and Time Predictions 2
People tend to underestimate the time it takes to accomplish tasks. This bias known
as the planning fallacy derives from the tendency to focus attention too narrowly on
the envisaged goal and to ignore additional information that could make predictions
more accurate and less biased. Drawing on recent research showing that power
induces attentional focus, four studies tested the hypothesis that power strengthens the
tendency to underestimate future task completion time. Across a range of task
domains, and using multiple operationalizations of power, including actual control
over outcomes (Study 1), priming (Studies 2 and 3), and individual differences (Study
4), power consistently led to more optimistic and less accurate time predictions.
Support was found for the role of attentional focus as an underlying mechanism for
those effects. Differences in optimism, self-efficacy, and mood did not contribute to
the greater bias in powerful individuals’ forecasts. We discuss the implications of
these findings for institutional decision processes and occupational health.
Power and Time Predictions 3
How Long Will It Take?
Power Biases Time Predictions
Time is a crucial factor in people’s everyday lives. Business executives,
policy makers, engineers, nurses, teachers or students routinely plan their work and
estimate the time it will take to accomplish tasks. Psychological research shows that
these estimates are systematically biased, and people tend to underestimate the time it
takes to accomplish tasks. Biased time predictions are a widespread phenomenon that
affects mundane everyday activities as well as large-scale business projects (e.g.,
Buehler, Griffin, & Ross, 1994; Hall, 1980; Schnaars, 1989). Unreliable time
predictions have attracted a great deal of public attention and are commonly known as
the planning fallacy (Kahneman & Tversky, 1979).
Considering the practical relevance and common interest, relatively little is
known about the factors that alter biases in time predictions. Interventions to reduce
the planning fallacy have had limited success overall (e.g., Byram, 1997; see Roy,
Christenfeld, & McKenzie, 2005, for a review). The present research extends past
research by focusing on the way the wider social context affects time predictions. In
particular, we suggest that being in a position of power strengthens the tendency to
underestimate future task completion time. Our proposal derives from recent research
indicating that power promotes a goal-directed attentional focus (e.g., Guinote,
2007a), and from the observation that biases in time predictions originate from a too
narrow focus on the envisaged goal.
Attentional Focus and Biased Time Predictions
Biased estimates of time originate from the ways individuals process
information (e.g., Newby-Clark, Ross, Buehler, Koehler, & Griffin, 2000; Buehler &
Griffin, 2003; Kahneman & Lovallo, 1993). Specifically, individuals tend to focus
Power and Time Predictions 4
attention too narrowly on the event in question and disregard additional information
that could make predictions more accurate and less optimistic. Below, we discuss
three sources of information that are commonly neglected.
Kahneman and Tversky (1979) suggested that when people plan the future
they adopt an ‘inside view’ that overemphasizes the uniqueness of a target event. By
ignoring the distribution of similar events people fail to consider how long similar
tasks usually take (see also Kahneman & Lovallo, 1993). Later research confirmed
that people are reluctant to consider past experiences in their planning, and this makes
them prone to bias in their forecasts (Buehler et al., 1994; Buehler & Griffin, 2003).
Underestimates of time also derive from the failure to take contingencies
sufficiently into account (e.g., Buehler et al., 1994). Future plans often resemble best-
case-scenarios and people tend to focus on the ways they can successfully accomplish
their goals (e.g., Newby-Clark et al., 2000). By ignoring alternative ways how the
future may unfold people are prone to misjudge impediments (e.g., Griffin, Dunning,
& Ross, 1990); a bias which sharply increases with the number of potential setbacks
Finally, people also tend to focus too heavily on a global representation of the
task at hand. As a result, they may not consider all subcomponents that a task affords
(Kruger & Evans, 2004; see also Fischhoff, Slovis, & Lichtenstein, 1987). Task
subcomponents that are less evident are especially at risk of being ignored (cf. Kruger
& Evans, 2004). Consistent with this reasoning, unpacking tasks into subcomponents
can decrease the tendency to underestimate task completion time (Kruger & Evans,
2004), and focusing attention on the intended outcome increases bias (e.g., Taylor,
Pham, Rivkin, & Armor, 1998).
Power and Time Predictions 5
In sum, biases in time predictions operate through attentional mechanisms.
People tend to focus too narrowly on the event in question and do not consider
sufficiently additional information that could make predictions more accurate. The
more people focus on the intended outcome, the more they are prone to bias in their
forecasts. Factors that alter people’s attentional focus can, therefore, strengthen or
alleviate the tendency to underestimate time. For example, enhancing people’s goal-
focus by means of instructions (Buehler & Griffin, 2003), or incentives (Buehler,
Griffin, & MacDonald, 1997; Byram, 1997) renders time predictions less accurate.
One social variable that has a profound impact on goal-directed attentional
focus is social power – the ability to influence and control others’ outcomes and
resources (see Fiske & Berdahl, 2007). As discussed next, individuals in power
display a processing orientation that should make them more prone to bias in
predictions of task completion time.
Power Affects Goal-Directed Attention
At the basic cognitive level, power fosters selective attention, enhancing the
processing of task relevant information and leading to the inhibition of secondary
information (Guinote, 2007b). Consequently, powerful individuals typically display a
more simplified, narrow focus of attention consistent with activated constructs (e.g.,
goals, needs, affordances), whereas powerless individuals pay less attention to
primary constructs and attend more to secondary information (see Guinote, 2007a, for
a review of the Situated Focus Theory of Power).
When goals are activated, powerful individuals pay more attention to
information that pertains to their focal goal, and less attention to secondary
information as compared to powerless individuals (Guinote, 2007b, 2007c; see also
Overbeck & Park, 2001; Slabu & Guinote, in press). For instance, research on social