Time Management
Too Optimistic in Time Planning?
Culture influences time estimates for completing tasks.
Updated February 2, 2026 Reviewed by Davia Sills
Key points
- People are often overly optimistic when estimating how much time they need to complete a task.
- This phenomenon, known as the planning fallacy, can be influenced by cultural differences.
- A person's time management skills can be improved by focusing on past experiences and social consequences.
People are often overly optimistic when estimating how much time they need to complete a task, be it a school assignment, preparing for a party, or shopping. They plan less time than they actually need and, as a result, fail to complete the task on time. This widely observed phenomenon is termed the planning fallacy.
Overoptimism Is Costly
The lack of sufficient time planning in everyday activities has consequences for the individual, such as failing a class, missing out on a party, or running out of food, all of which can be stress-provoking. Yet the consequences are more severe and long-lasting when it comes to large, public projects.
One of the most infamously delayed and expensive infrastructure projects in U.S. history is the Boston Big Dig (Central Artery/Tunnel Project), which was originally planned to be completed in 1998. It ended up being completed at the end of 2007, about 9 years late. Accompanying the delay were massive financial costs, rising from the initial estimated cost of $2.8 billion to a final cost of over $8 billion, or nearly $22 billion when factoring in interest and related projects.
The Causes
Many factors may contribute to the overoptimistic estimation of task completion times. One is that people typically focus on positive future outcomes when planning their time. As a result, they disregard past experience of similar tasks that ran over schedule. Instead, they believe that “this time will be different.”
Motivational factors also play a role. Due to self-serving bias, people often blame external or unstable causes (e.g., the task being too difficult) for their failures to meet deadlines while overlooking their own responsibilities. This makes it harder for them to appreciate the relevance of past experiences in guiding their time planning.
The Influence of Culture
Although the planning fallacy may be a universal cognitive bias, cultural factors may shape whether and to what extent it is manifested in specific situations.
Asian cultures place greater emphasis on the intellectual value of the past in relation to the future than Western cultures do. Also, while Western cultures emphasize self-enhancement, Asian cultures emphasize self-improvement. Accordingly, Western individuals often focus on external factors when they fail to avoid feeling bad, whereas Asians often reflect on their own deficiencies or mistakes (e.g., a lack of effort) to learn lessons.
When reminded of similar past experiences, will Asians be more likely than Westerners to consider the information and make more realistic plans?
Furthermore, Asian cultures promote interdependence and social harmony, whereas Western cultures, particularly European American ones, endorse independence and personal autonomy. Accordingly, compared with their Western counterparts, Asians are often more concerned about others’ opinions, more wary of burdening others, and more willing to adapt to others’ needs.
When reminded that their insufficient planning will have negative consequences for others, will Asians make less optimistic and more realistic plans than Westerners?
An Empirical Test
We conducted two studies to answer these questions. European American and Asian community adults (Study 1) and European American, Asian American, and Chinese college students (Study 2) were randomly assigned to one of three conditions and asked to predict how much time they’d need to complete familiar tasks in hypothetical scenarios.
In the lesson-learning condition, participants were first reminded of the last time they engaged in the same task before making their time prediction. For example:
Think about last time you did grocery shopping in the supermarket.
Imagine you are grocery shopping in the supermarket. How long do you think it will take you to finish shopping?
0.25 hours ————--— 4 hours
In the social consequence condition, participants were warned that others would be negatively affected if they failed to complete the task within their predicted time. For example:
Imagine you are grocery shopping in the supermarket. How long do you think it will take you to finish shopping? Note that if you fail to finish shopping within the time you plan, you will miss your appointment with your friend.
0.25 hours ————--— 4 hours
In the control condition, participants simply predicted how long it would take them to complete the tasks without the reminder or warning.
The results showed that when reminded of relevant past experiences or warned about the social consequences of insufficient planning, Asian adults, but not European Americans, made longer and thus less optimistic time plans than those in the control condition. Among the college students, while European Americans, Asian Americans, and Chinese all predicted longer times in the two experimental conditions than controls, Chinese college students made the largest increase in their time predictions.
Thus, the answer to both questions above is Yes.
Take-Home Messages
Cultural factors, such as attitudes toward the past and an independent-interdependent orientation, shape how people plan their time to complete everyday tasks. Although the planning fallacy may be universal, participants in the control condition made similarly optimistic time estimates across cultures; it can be influenced by situational factors (e.g., historical data, social impact) in ways that align with cultural belief systems.
These findings can inform interventions to help individuals and institutions reduce overoptimism and make more realistic time plans. For example, prior to the planning, people can reflect on similar past projects in which they failed to live up to their expectations and imagine negative social or societal consequences from insufficient planning. These strategies require repeated practice for individuals and groups that do not highly value the past or closely attend to others’ needs.
References
Guan, L., & Wang, Q. (2026). “I Can Do It in No Time!” Time Predictions in the Cultural Context. Journal of Cross-Cultural Psychology. https://doi.org/10.1177/00220221261418305
