Savanna Hypothesis of Landscape Preference

The savanna hypothesis, also known as the savanna theory or the habitat selection hypothesis, proposes that human aesthetic preferences for certain types of natural environments are not arbitrary but are deeply rooted in our evolutionary history. Specifically, it suggests that humans exhibit an innate preference for landscapes that resemble the East African savanna, the environment in which much of human evolution is believed to have taken place. These landscapes are typically characterized by open grasslands, scattered trees, and the presence of water, offering a balance of resources, refuge, and visibility that would have been crucial for survival for early hominins.

Origins and Core Argument

The idea that humans possess an evolved preference for specific environments was first systematically articulated by Orians (1980) and later expanded by Orians and Heerwagen (1992). They drew upon principles of evolutionary biology and behavioral ecology, noting that many animal species exhibit innate habitat preferences that guide them towards optimal environments for their survival and reproduction. For instance, birds often have preferences for specific nesting sites or foraging grounds that maximize their fitness. The savanna hypothesis extends this logic to humans, arguing that our ancestors, facing constant selective pressures, would have benefited from a psychological mechanism that predisposed them to seek out and settle in environments offering abundant resources and minimal threats.

According to the hypothesis, the East African savanna provided an ideal balance of critical resources. The open grasslands allowed for long-distance visibility, crucial for spotting predators and prey. Scattered trees offered shade, shelter from elements, and elevated vantage points for observation, as well as potential sources of food (fruits, nuts) and wood for tools or fire. The proximity to water sources was essential for hydration and often attracted game. This combination of features would have provided a high-quality habitat, and individuals with a psychological predisposition to prefer such environments would have had a survival advantage, leading to the entrenchment of this preference over evolutionary time.

Evidence and Supporting Research

Empirical support for the savanna hypothesis comes from various fields, including environmental psychology, anthropology, and cross-cultural studies. Stephen and Rachel Kaplan (1989) developed the 'preference matrix' or 'information processing theory' of landscape preference, which, while broader than the savanna hypothesis, aligns with its core tenets. They proposed that people prefer environments that offer both coherence (ease of understanding) and complexity (richness of information), as well as legibility (ease of navigation) and mystery (promise of more information). Savanna-like landscapes often fit these criteria well, offering clear sightlines (coherence, legibility) alongside varied vegetation and distant features (complexity, mystery).

Numerous studies have investigated landscape preferences across different cultures and age groups. For example, Balling and Falk (1982) conducted a seminal study with children from various age groups, showing them slides of different biomes (e.g., savanna, desert, tropical forest, coniferous forest). They found that children, particularly those aged 8–12, consistently rated savanna landscapes as most preferred, regardless of their cultural background or current residential environment. This finding is often cited as evidence for an innate, rather than purely learned, preference.

Further research by Falk and Balling (2009) and others has replicated these findings, demonstrating a consistent preference for savanna-like features, such as moderate tree density, open ground, and the presence of water. Studies using virtual reality and eye-tracking technologies have also shown that individuals tend to spend more time looking at and report higher aesthetic pleasure from images depicting savanna-like scenes compared to other biomes (e.g., Joye, 2007).

Architectural and urban planning implications have also been explored. Appleton (1975) introduced the 'prospect-refuge theory,' which, while distinct, complements the savanna hypothesis. Prospect-refuge theory suggests that humans prefer environments that offer both an unimpeded view (prospect) and a place of concealment or safety (refuge). Savanna landscapes inherently provide both: open vistas for prospect and scattered trees or elevated ground for refuge. This framework helps explain why features like balconies, windows overlooking open spaces, and parks with scattered trees are often highly valued in built environments.

Critiques and Alternative Perspectives

Despite its widespread influence, the savanna hypothesis has faced several criticisms. One common critique revolves around the difficulty of definitively separating innate preferences from culturally learned ones. While studies with children from diverse backgrounds offer some support for innateness, critics argue that exposure to media, art, and cultural narratives that often idealize certain natural settings could still influence preferences (e.g., Gobster & Chenoweth, 1989).

Another point of contention is the oversimplification of human evolutionary history. While East Africa was a crucial locus for hominin evolution, humans have also adapted to and thrived in a wide array of environments, including forests, deserts, mountains, and coastal areas. Critics like Buller (2005) argue that focusing solely on the savanna as the 'ancestral environment' ignores the diversity of human adaptive challenges and the plasticity of human behavior and preferences. If humans were truly adapted only to savannas, it would be difficult to explain their successful colonization of the entire globe.

Some researchers propose that human landscape preferences are more flexible and context-dependent than the savanna hypothesis suggests. For instance, the 'biophilia hypothesis' (Wilson, 1984) posits a broader innate tendency to connect with nature and other living systems, without specifying a particular landscape type. This perspective suggests that the elements of nature (water, vegetation, animals) rather than a specific configuration of a landscape, are the primary drivers of preference. Others argue for a 'habitat generalist' view, suggesting that humans evolved to be highly adaptable and to appreciate a wide range of environments that offer resources, rather than being hardwired for one specific type.

Furthermore, the operationalization of 'savanna-like' can be vague. What constitutes a savanna? Is it merely open space with trees, or are specific tree species, grass types, and animal presence required? The precise features that elicit preference and their relative importance are still subjects of ongoing research.

Open Questions

Future research continues to explore the nuances of human landscape preference. Questions remain regarding the specific psychological mechanisms underlying these preferences. Are they primarily aesthetic, or do they involve deeper cognitive processes related to resource assessment and threat detection? How do individual differences, cultural background, and personal experiences interact with any potential innate predispositions?

Investigating the neurobiological underpinnings of landscape preference using techniques like fMRI could provide further insights into whether certain brain regions are consistently activated by savanna-like stimuli. Additionally, exploring how modern urban environments can be designed to incorporate elements that tap into these hypothesized preferences, potentially enhancing well-being and reducing stress, remains a significant area of applied research. The savanna hypothesis continues to serve as a foundational framework for understanding the deep evolutionary roots of human aesthetic and environmental choices.