A bird’s eye perspective on the global human day

By Bhavana KunkalikarReviewed by Lily Ramsey, LLMJun 14 2023

In a recent study published in the Proceedings of the National Academy of Sciences (PNAS) Journal, researchers used a physical outcome-based categorization to calculate how humans spend their day.

Study: The global human day. Image Credit: SurfsUp/Shutterstock.com

Background

Human activity studies have been widely studied, while activities that are fundamental aspects of human behavior have been extensively examined by various fields such as sociology, economics, history, and anthropology.

Yet, a comprehensive worldwide understanding of human activities is currently lacking. Unlike monetary estimates, which are not physical, humans have a fixed 24 hours per day and utilize every minute of it in some activity.

To take full advantage of the 24-hour time limit, it is necessary to evaluate all activities comprehensively. Combining sociological and economic time-use data with a unified set of activity categories can resolve the disciplinary distinction between paid and unpaid activities.

About the study

The authors present a comprehensive calculation of the average daily activities of humans worldwide, referred to as the global human day.

The global human day estimate is created through the Human Chronome Project, which utilizes nationally representative time use surveys, working time, national employment statistics, and a multicomponent time use model for individuals aged between zero and 17 years. Wearable device sleep data is also incorporated to compare with time-use survey data.

Time use surveys from 58 countries, representing around 60% of the world population, were employed to establish a mean daily time use baseline. Various methods were used to collect survey data, including self-completed time diaries, in-person or telephonic interviews, and online questionnaires.

The measure utilized in this study is the population-weighted average daily time spent on all assessed activities among all participants, calculated by multiplying participant rate and participant time.

The average daily working duration of the entire population was calculated using average annual employment and average weekly working duration data from the International Standard Industrial Classification (ISIC) of economic activities.

Results

The study estimated the average time humans spend on various daily activities. The largest category involved sleep and bed rest. The estimated sleep duration is higher than the global average of 7.5 hours per day for adults recorded by wearable devices. This difference is due to the inclusion of children in the estimate and the time spent in bed without sleeping.

Three major groups can be identified that summarize the subcategories of human activity during the approximately 15 hours per day that are not spent sleeping or resting in bed. The largest group of outcomes, direct human outcomes, is driven by their immediate impact on people and accounts for 9.4 hours.

These activities involve maintaining the hygiene and health of the human body, intentionally altering neural pathways, and creating specific experiences. Social, passive, and interactive activities, such as reading, playing games, watching screens, socializing, going for walks, and sitting doing nothing, account for an average of 4.6 ± 0.3 hours or approximately 31% of the mean waking day, making it the most time-consuming subcategory.

The second largest group of activities, which takes up 3.4 hours, is focused on producing physical alterations in the world outside humans and is driven by external outcomes. These changes involve various activities such as extracting resources and energy from nature, producing food, constructing movable and immovable objects, and ensuring cleanliness and orderliness in human living spaces.

The third group's activities are driven by organizational goals, such as relocating people and materials. Additionally, some activities do not have a specific physical outcome but instead manage human time and access human rights.

Approximately 11% of the total human day, or almost 2.6 hours, is dedicated to economic activities, amounting to one-sixth of the average waking hours over a lifetime. This duration may seem insignificant, but it is comparable to a full-time work week of 41 hours for workers worldwide.

The data highlight significant patterns in four activities compared to gross domestic product (GDP) per capita. In low-income countries, a significant amount of time is dedicated to growing and gathering food, while in high-income countries, this time is greatly reduced.

The significant increase in food production can be attributed to labor-saving technologies that have reduced the time required to produce the same amount. The reduction of food growth and collection time by 1.2 hours across different income levels is compensated by a rise in the duration of experience-based pursuits.

Conclusion

Most human waking hours are dedicated to activities that directly benefit human minds and bodies, totaling 9.4 hours daily.

On the other hand, only 3.4 hours per day are spent on altering our surroundings and the world outside, while 2.1 hours per day are allocated for social process organization and transportation.

The team also noted that, on average, humans spend about five minutes per day on direct extraction and one minute per day on waste management.

This indicates a significant potential to adjust the time allocation for these activities. The study offers a fundamental measurement of the time distribution of human life on a global scale, which can be utilized in various research areas.