Environmental Psychology is the study of the relationship between people and their physical environment. They look at how psychological processes (emotions, behaviours and cognitions) are place-related and place-dependent. In other words, they look at how environments influence people -- as well as on how people influence the environment. We speak to Melissa Marselle, academic, writer and environmental psychologist about patterns in nature and how creating a biodiverse environment has positive impact not just on the natural world but also us as human beings and our cognitive and physical health. We also speak about Goldilocks... We all have preferences, and our preference for one thing over another can influence our behaviour. For example, your preference for a type of ice cream will influence which one you buy in store. Likewise there will be physical characteristics of an environment (e.g. urban vs. natural, water, land use type, open spatial arrangement, spatial definition, tree size, tree density) that you have a preference. Kaplan and Kaplan’s “Preference Matrix’ is a theory about preference based on the information that an environment provides, rather than for its aesthetic beauty. Think about the times when you need to understand an environment immediately – you just walked into a busy department store or get off a bus in the city centre -- in order to understand where you are and how we can get from here to there, you need to obtain information from that environment. According to the Kaplan’s preference theory, that, generally, a preferred environment is one that supports quick information processing, understanding and exploration. There are design aspects in an environment that can help provide information, such as an environment legibility, coherence, complexity. In the Preference Matrix biodiversity is implicitly mentioned as complexity. The Kaplan’s discuss an environment’s “diversity” and “richness” when describing the information quality of complexity in an environment. Complexity in this context refers to how much there is to look at and think about; too much complexity and the environment cannot be understood and is confusing, but too little complexity and the individual is bored and not motivated to explore. The preference matrix would say that moderate amount of complexity would be preferred. Think about story of Goldilocks and the 3 bears, she chose the middle one. Stress reduction theory also considers biodiversity as part of an environment’s complexity, and also hypothesizes that environments with a moderate amount of biodiversity will be the best for stress recovery. A experimental study tested this by looked at whether biodiversity of a meadow could reduce stress. They measured people’s blood pressure while they looked at meadows of various number of herb and grass species for 2 minutes. The abundance of plants were all the same, the researchers just changed the number of species types. They found people were most relaxed when looking a meadows of about 30 different species, and least relaxed when looking at meadows with no species or 60 different species. Melissa and colleagues created a biodiversity-health framework model detailing the various causal pathways—both beneficial as well as harmful— that link biodiversity with human health: (i) reducing harm (e.g. provision of medicines, decreasing exposure to air and noise pollution); (ii) restoring capacities (e.g. attention restoration, stress reduction); (iii) building capacities (e.g. promoting physical activity, transcendent experiences); and (iv) causing harm (e.g. dangerous wildlife, zoonotic diseases, allergens). The restoring capacities domain of pathways refers to the recovery of adaptive capabilities that have been diminished through the demands of dealing with everyday life. Over time, lack of restoration of these resources can lead to mental and physical ill health. The restoring capacities pathway highlights how biodiversity can contribute to