Ask an Expert

How Environmental Generational Amnesia Affects Our Mental Health

  • Published24 Jul 2023
  • Author Robin Tricoles
  • Source BrainFacts/SfN

Most people are familiar with amnesia, the inability to recall events that happen before or after a significant incident, such as a head injury. But what about environmental generational amnesia or EGA, the phenomena by which across generations, the norm for a healthy, natural world declines?

Each generation largely accepts the environment they are born into as nature’s norm, no matter how degraded that environment may be. Studies have shown that urbanization is linked to mental illness, such as depression, which is why access to nature in urbanized areas may improve mental health. A recent study even suggests greater exposure to green space may also slow genetic aging, though the effect varies across race, gender, and socioeconomic status. Another study indicates a 90-minute nature walk elicits beneficial neural activity in a part of the brain associated with depression and anxiety.

Peter Kahn, director of the Human Interaction with Nature and Technological Systems (HINTS) Lab at the University of Washington, coined the phrase “environmental generational amnesia” and calls EGA “one of the fundamental, deepest psychological problems of our lifetime.” The psychology professor studies the rapid degradation of the natural world and the acceleration of technological advances. speaks with Kahn about how EGA affects our psyches and brains, as well as ways to address this collective blind spot and why it is necessary to do so. For Kahn, understanding EGA is where we start to fight climate change.

What is environmental generational amnesia?

Peter Kahn
Peter Kahn 

When I was a teenager, I would ride my horse deep into the Northern California wilderness. I came of age living in big nature. Given California’s growth and development, that ride would now be impossible. Yet phylogenetically, big nature is deep in all of our psyches. So I began to wonder why we were so rapidly destroying it. Years later at my first job at the University of Houston, I was studying children and parents’ environmental views and values. I found the children knew what air pollution was; but when we asked them if Houston had a problem with air pollution, they said, “No, we don’t have pollution here.” At the time, Houston was the most polluted city in the United States.

How do you explain that? For me as a developmental psychologist, this was about children constructing knowledge. It’s a constructivist process of each generation born into a specific environment, understanding what is a healthy, rich, and biodiverse environment. But it’s almost always impoverished compared with previous generations. And we don’t realize it: That is environmental generational amnesia.

Why does EGA matter?

Climate change is upon us. It is more like climate havoc and destruction. We think we understand the magnitude of the problem because we experience some of the effects of extreme weather events such as floods, droughts, and heatwaves. But because of EGA, we keep adjusting our baseline of what “normal” is. EGA is part of the reason we got to this point. Due to EGA, we could never fully recognize the harms that have been occurring, or — and this is equally important — the benefits that we have been losing. Being immersed in a biodiverse natural world is not just about creating conditions for our physical health, but for our psychological wellbeing and flourishing, and our sense wonder, joy, and awe.

Also, one of my collaborators, Gregory Bratman, published a study showing that a 90-minute nature walk versus a walk in an urban setting reduced rumination and reduced neural activity in the subgenual prefrontal cortex, a part of the brain linked to mental illness. Rumination involves repetitive negative thoughts about oneself and has been shown to predict depression. So this study suggests interaction with easy-to-reach natural areas is important to our mental health. And that’s one way to push back on EGA.

One of your studies explored the ways children interact with “big nature.” What is big nature, and how do children’s interactions with it affect their development?

I use the term big nature in two ways. It refers to nature that is largely untamed, unmanaged, not encompassed, and unencumbered and unmediated by technology. But “big” is also a relative concept. For a child growing up in a megacity, big nature could be going outdoors and encountering squirrels or birds or playing in an urban fountain. We conducted an observational study of children in a forest preschool to learn how their early contact with nature helped them develop environmental abilities and values. We observed, for example, how children tripped over rocks, roots, stumps, and sticks. They thereby learned how to fall down safely or avoid falling in a natural environment. Both are important developmental achievements and provide confidence for being in nature.

How can we address this collective amnesia and generational acceptance of increased urbanization and a lack of nature?

What we need is deeper and richer interactions with nature through what I call interaction patterns and interaction pattern design. Interaction patterns are essential ways of interacting with nature described abstractly enough such that the pattern can be instantiated in different ways, across diverse forms of nature. Some patterns include walking along the edge of water and land, watching a sunset, swimming in water, hearing bird songs, or smelling flowers. We have delineated over 500 such interaction patterns that can be used in urban planning. For example, if there is an urban lake, build a pathway around it, so that people can walk or bike along the edge of water and land. Or if you are building a concrete urban fountain, build it so that there are edges to walk along the water and concrete. Interaction pattern design can be used at an individual level, architectural level, or urban-design level, and that kind of intention helps solve the problem of EGA.

This interview has been edited for length and clarity.

Bratman, G. N., Hamilton, J. P., Hahn, K. S., Gross, J. J. (2015). Nature experience reduces rumination and subgenual prefrontal cortex activation. Proceedings of the National Academy of Sciences, 112(28) 8567-8572.

Kahn, P. H. & Friedman, B. (1998). On Nature and Environmental Education: black parents speak from the inner city, Environmental Education Research, 4:1, 25-39. 

Kahn, P. H., Jr. & Weiss, T. (2017). The importance of children interacting with big nature. Children, youth and environments, 27(2) 7-24.
Ask an Expert welcomes all your brain-related questions.

Every month, we choose one reader question and get an answer from a top neuroscientist. Always been curious about something?

Neuroscience in the News

Check out the latest news from the field.

Read More

Educator Resources

Explain the brain to your students with a variety of teaching tools and resources.


Core Concepts

A beginner's guide to the brain and nervous system.