Biologically Based Design 

The positive effects of biophilic design must be understood in architectural terms: as form and form-making principles, and structural systems. Biologically-based design utilizes observed effects, and tries to document them into an empirical and tested body of knowledge. At the same time, an extensive research program is beginning to uncover the deeper causes for these effects: i.e., a possible innate reaction to the specific geometry of natural forms, detail, hierarchical subdivisions, color, etc. Since this project is far broader than the traditional study of architecture, designers must actively solicit help from other disciplines whose knowledge can help to explain human response to design. It is essential not to be partial in any way, since, in addition to known factors, there are clearly unknown factors playing a role yet to be discovered. 

Recent investigations lead us inescapably to the fact that we engage emotionally with the built environment through architectural forms and surfaces. We experience our surroundings no differently than we experience natural environments, other living creatures, and other human beings. We relate to details, surfaces, and architectural spaces in much the same way as we relate to domestic animals such as our pets. The mechanism through which we engage with subjects outside ourselves relies on a connection established via information exchange. Our neurological mechanism reacts to the information field (the transmission component), while inducing a reaction in the state of our body (the physiological component). Some of the highest levels of sensory connection to the built environment have been evidenced in the great buildings and urban spaces of the past (Alexander, 2002-2005; Salingaros, 2005; 2006). Both natural and built environments possess intrinsic qualities that enable such a strong connection, and which in turn can be healing. This works through the sense of wellbeing established and maintained in the life of those who engage with such a structure. Great architects in the past were better able to discern those qualities, and to reproduce them in their buildings, because they were more engaged with their immediate surroundings.

What we are depends on the natural environment that shaped our bodies and senses (Kellert, 2005; Kellert & Wilson, 1993; Orians & Heerwagen, 1992). Far from being able to liberate our modern selves from our historical development, we inherit our biological origin in the structure of our mind and body. Nature has built on top of this over successive millennia, in increasing layers of sophistication. Evolution works by using what is already there, extending and recombining existing pieces to make something new. We thus depend on the presence of certain determinant qualities in the environment not only for our existence, but equally for our sense of belonging and wellbeing. Denying this genetic dependence is akin to denying our necessity for food and air. The typologies of traditional and vernacular architectures are predicated on biological necessity. They are not romantic expressions (as some would have us believe), but in fact a primal source of neurological nourishment.

A new chapter in scientific investigation is beginning to document environmental factors that affect our physiological wellbeing. Going beyond the century-old debates on aesthetics, a neurological basis for aesthetic response is now being established (Ramachandran & Rogers-Ramachandran, 2006). The mechanism for neurological nourishment was recently discovered in studies using Functional Magnetic Resonance Imaging. Humans have an innate hunger for certain types of information: the circuits for this have been associated with the brain’s pleasure centers, which also control the reduction of pain (Biederman & Vessel, 2006). It is easy to hypothesize that this neurophysiologic mechanism is the result of an advantageous evolutionary adaptation. 

A growing amount of research finds that fractal qualities in our environment (i.e., ordered details arranged in a nested scaling hierarchy) contribute positively to human wellbeing (Hagerhall, Purcell & Taylor, 2004; Taylor, 2006; Taylor et. al., 2005). Gothic architecture is intrinsically fractal, and has been conjectured to be an externalization of the fractal patterns of our brain’s neural organization (Goldberger, 1996). The parallel between built fractal patterns and possible cerebral organization is too strong to be a coincidence (Salingaros, 2006). This idea is supported independently by the way we perceive and find meaning in patterns in our environment (Kellert, 2005; Salingaros, 2006). It is no surprise then that humans build those patterns into their creations. Investigations of all traditional architectural and urban forms and ornamentation confirm their essentially fractal qualities (Crompton, 2002; Salingaros, 2005; 2006). 

Another direction of research has uncovered undisputed clinical advantages (faster hospital healing) of natural environments, including artificial environments mimicking geometrical qualities of natural environments (Frumkin, 2001; Ulrich, 1984; 2000). Pain relief in hospital settings is significantly improved by viewing natural (or videos of natural) environments (Tse et. al., 2002), thus confirming the link between specific types of informational input and pain reduction. These developments have sparked the interest of organizations concerned with improving the positive human qualities of their spaces. Much of this research has started to be applied in the field of interior design rather than architecture (Augustin & Wise, 2000; Wise & Leigh-Hazzard, 2002). There are principally two reasons for this: first, interiors are much easier to manipulate than entire buildings; and second, environments for work, leisure, or health care can make a more immediate and substantive difference in human wellbeing and performance.

Reviewing the positive effect that fractals and natural complexity have on humans, Yannick Joye (2006; 2007a; 2007b) reinforces our own conclusions on the essential “hard-wired” nature of the process. This is not the result of a conscious response to recognizing fractal or complex patterns in the environment: it is built into our neural system. Reaction to a neurologically-nourishing environment is physiological (i.e. emotional) rather than intellectual. There is mounting evidence of an innate information-processing system that has evolved along with the rest of our physiology (Joye, 2006; 2007a; 2007b). This system is acutely tuned to the visual complexity of the natural environment, specifically to respond positively to the highest levels of organized complexity (Salingaros, 2006). 

Some researchers concentrate on human response to fractal qualities, whereas others measure the benefits of the complex geometry found in natural forms. Fractals are an important component of this effect, but by no means represent the full gamut of connective qualities. Additional geometrical properties of natural/biological forms clearly contribute to a positive physiological response in humans (Alexander, 2002-2005; Enquist & Arak, 1994; Kellert, 2005; Klinger & Salingaros, 2000; Salingaros, 2005; 2006). Symmetry — more precisely, a hierarchy of subsymmetries on many distinct scales — plays a crucial role. The overall perceived complexity is better understood using a multi-dimensional model rather than the simplistic one-dimensional model of plainness versus complication. Not only the presence of information, but especially how that information is organized, produces a positive or negative effect on our perceptive system (Klinger & Salingaros, 2000; Salingaros, 2006). 

We assume an underlying genetic factor as the basis for why the ordered geometry of biological forms connects with and leads to healing effects on human beings. Many scientists now believe that evolution has a direction: the increasing complexity from emergent life forms in a primordial soup to human beings is not random (Conway-Morris, 2003). While not speaking of “purpose”, we may discern a flow of organization towards a very specific type of organized complexity (Carroll, 2001; Valentine, Collins & Meyer, 1994). As such, evolution becomes understandable in informational terms, where adaptive forces act in a fairly restricted direction (though without an end result in sight). Some species do reach a complexity plateau, and individual organismic components may simplify as a result of adaptation, yet the strand of human evolution has moved towards increasing complexity. A corollary to this conclusion is that all life forms share an informational kinship based on very special geometrical complexity, which builds up in a cumulative process. The built environment, considered as an externalization of intrinsic human complexity fits better in the larger scheme of things whenever it follows the same informational template. The design of our buildings and cities should therefore try and adapt to the evolutionary direction of biological life in the universe.

Biophilic Architecture and Neurological Nourishment

Human beings connect physiologically and psychologically to structures embodying organized complexity more strongly than to environments that are either too plain, or which present disorganized complexity (Salingaros, 2006). It follows that the built environment performs a crucial function — in some instances to the same degree — as does the natural environment. The connection process (outlined in the following sections) plays a key role in our lives, because it influences our health and mental wellbeing. Studying the geometrical characteristics of the type of visual complexity responsible for positive effects reveals its commonality with biological structures. Applying such concepts to architecture leads to two distinct conclusions. First, that we should bring as much of nature as we can into our everyday environments so as to experience it first-hand; and second, that we need to shape our built environment to incorporate those same geometrical qualities found in nature.

Human beings are biologically predisposed to require contact with natural forms. Following the arguments of Edward Wilson (1984), people are not capable of living a complete and healthy life detached from nature. By this, Wilson means that we benefit from direct contact with living biological forms, and not the poor substitute we see in so many urban and architectural settings today. Wilson’s Biophilia Hypothesis asserts that we need contact with nature, and with the complex geometry of natural forms, just as much as we require nutrients and air for our metabolism (Kellert, 2005; Kellert & Wilson, 1993).

One aspect of biophilic architecture, therefore, is the intimate merging of artificial structures with natural structures. This could involve bringing nature into a building, using natural materials and surfaces, allowing natural light, and incorporating plants into the structure. It also means setting a building within a natural environment instead of simply erasing nature to erect the building (Kellert, 2005). While many architects may indeed claim to practice in this way, they more frequently replace nature by a very poor image of nature: an artificial representation or substitute that lacks the requisite complexity. That is in keeping with the abstract conception of architecture that has been applied throughout the twentieth century, and which continues today. Strips of lawn and a few interior potted plants do not represent anything but an abstraction of nature; not the real thing. This is a minimalist image lacking complexity and hierarchy. Biophilia demands a vastly more intense connection with plant and animal life, leading to the support of ecosystems and native plant species whenever possible.

Some good solutions incorporate small ecosystems consisting of a rich combination of plants within a building, or in a building’s garden or courtyard. A flat lawn, by contrast, while better than a rectangular concrete slab, represents the same visual purity (emptiness) as the plain slab. Our senses perceive it as a single scale and are unable to connect to it fractally. Moreover, lawn is an ecological monoculture irrelevant to local ecology, because it exists on a single ecological scale. Nature exhibits ecological complexity: interacting plants that in turn provide visual complexity, which is a source of neurological nourishment. Not surprisingly, this way of thinking leads to buildings that are more sustainable, and which incorporate natural processes that help in energy efficiency. Sustainability goes hand-in-hand with a new respect for nature coming from biophilia (Kellert, 2005).

For all its benefits of helping users to connect with nature in their everyday interior work environment, this first approach is only a partial solution. The biophilic element here is plant life brought next to and into a building, but the building itself could still be made in an alien or artificial form and built using artificial materials. Human connection is then possible only with the plant forms, but never with the building itself. This problem is particularly acute in an age where the majority of architects use industrial materials and modernist typologies without question. This practice only serves to undermine the requisite natural connections that humans need. The natural aspect of an industrial building-plus-garden is simply a biological component grafted onto an armature that is fundamentally hostile to human sensibilities. There is always a sharp contrast between the building and the natural elements that it encloses. It still triggers an underlying neurological disconnection on a basic level.

A second, and much deeper aspect of biophilic architecture requires us to incorporate the essential geometrical qualities of nature into the building and urban structure. This implies a more complex built geometry, following the same complexity as natural forms themselves. Once again, there is a danger of misunderstanding this geometry and superficially copying shapes that are irrelevant to a particular building or city. Architectural magazines are full of images of organic-looking (and unrealizable) buildings; whereas we actually mean ordinary-looking buildings that are more adapted to human sensibilities. For example, making a giant copy of an organism out of industrial materials becomes an iconic statement that fails to provide any level of connectivity. The shape of a giant mollusk, crab, amoeba, or centipede is still an abstract concept imposed on a building; little better in quality of abstraction from a giant box or rectangular slab. That belies a fundamental misconception about living structure, which connects on the human levels of scale through organized details and hierarchical connections (Alexander, 2002-2005; Salingaros, 2005; 2006). 

Neurological nourishment depends upon an engagement with information and its organization. This connective mechanism acts on all geometrical levels, from the microscopic, through increasing physical scales up to the size of the city. The correct connective rules were rediscovered repeatedly by traditional societies, and are applied throughout historic and vernacular architectures. Traditional ornamentation, color, articulated surfaces, and the shape of interior space helped to achieve informational connectivity. Long misinterpreted as a copy of natural forms, ornamentation in its deepest expressions is far more than that: it is a distillation of geometrical connective rules that trigger our neurophysiology directly. These qualities are emphatically not present in the dominant architectural ideology of the twentieth century. 

Some biophilic architects consider that neurological nourishment comes strictly from living biological forms. In their view, ornamented forms and surfaces are derivative of natural forms, and thus provide only a second-hand (i.e. vicarious) experience. We, on the other hand, believe that the underlying geometrical complexity of living structure is what nourishes humans. This geometry could be equally expressed in biological organisms as in artifacts and buildings: the difference is merely one of degree (Alexander, 2002-2005). If implemented correctly, it is not neurologically discernable, only more or less intense. Every living being incorporates this essential geometry to an astonishing degree (in its physical form), whereas only the greatest of human creations even come close. In this view, the distinction between the living and the artificial is left intentionally vague, and life itself is drawn closer to geometry. At the same time, this approach helps to explain the intense connection people feel with certain inanimate objects, i.e. the artifacts and creations of our human past.

Traditional techniques for creating neurologically-nourishing structures are wedded to spiritual explanations, which are often unacceptable to contemporary architects (and to business clients). Not surprisingly, the most intense connection is achieved in historic sacred sites, buildings, and artifacts. It is only in recent times that a scientific explanation has been given for what were originally religious/mystical practices of architecture and design (Alexander, 2002-2005; Salingaros, 2006). Today, it is finally possible to build an intensely connective building and justify it scientifically, by extending the geometrical logic of the natural world into the built world.

To summarize, two branches of contemporary biophilic architecture are beginning to be practiced today (Kellert, 2005). One basically continues to use industrial typologies but incorporates plants and natural features in a nontrivial manner; while the other alters the building materials, surfaces, and geometry themselves so that they connect neurologically to the user. This second type ties in more deeply to older, traditional, sacred, and vernacular architectures. So far, the first (high-tech) method has an advantage over the second (mathematical/sacred) method, because it is already in line with the industrial building/economic engine of our global society. Visually and philosophically very distinct, nevertheless, these two movements are contributing to a rediscovery of our immediate connection to the environment.

Perhaps the greatest impact of the biophilic movement is to establish a value system for a particular group of essential geometric qualities. Living forms and the geometrical characteristics they embody must be protected from destruction, because they provide us with neurological nourishment (Wilson, 1984). This is the seed for conservation, both of biological species, as well as for historic and traditional architectures.

An Architecture That Arises From Human Nature

The desire to overcome nature, to separate man from the universe by placing him above natural constraints, led to the ultimate architectural assertion of the twentieth century, one expressing total autonomy. Adaptive processes were replaced by a formalized, self-referential, autonomous architectural order. The degree of separation that architecture placed between itself and nature was celebrated as a great accomplishment. This architectural movement culminated in the 1970s with the declaration made about an exhibition of current design work: “This spectacularly beautiful work, elegant, formal, and totally detached from the world around it, represents a kind of counterrevolution in today’s educational thought and practice.” (Huxtable, 1999). Indeed, the value of twentieth-century architecture was now solely predicated on its degree of separation from the world around it: the world in which humans seek comfort and shelter (Masden, 2006). 

To consider the service of architecture as something other than human seems contradictory to its very inception, for it was human nature that first gave it form by compelling humans to build. If we are to consider whom architecture should serve, and re-establish the relationship between architecture and humanity, then we must consider the essence of human nature, and grasp how human beings came to create particular kinds of structures. We must account for the neurological processes that operate as our interface with the physical world, and ask why, if these processes are intrinsically human, were we ever able to stray so far away from this human dimension.

Edward Wilson’s seminal book On Human Nature (Wilson, 1978) laid the groundwork for understanding our biological nature, explaining how our actions are determined to a large part by genetic structure and evolution. Wilson thus places human actions on a sound biological foundation. Even so, people often contradict their biological nature by acting against it without any apparent logic, as when they join a mass movement (Hoffer, 1951). People are sometimes manipulated into adopting an ideology, which then controls their actions in violation of their biological nature (Salingaros, 2004). 

These ideas are relevant to architecture in a positive sense. The early stages of the artistic process are a result of a vast number of unconscious forces and impulses. To initiate this process towards a healthier architecture, we need to ask: what are the tactile, perceptual, and mental processes necessary for a human sense of wellbeing? We are not going to describe how to incorporate biological elements into the built environment — the principal component of biophilic design — since that is dealt with by other authors (Kellert, 2005). Rather, we have developed techniques for design and construction that use materials to create a source of neurological nourishment. We draw from comprehensive architectural design methods developed only recently (Alexander, 2002-2005; Salingaros, 2005; 2006; Salingaros & Masden, 2007). 

Several suggestions can help to implement this program. Appendix I to this Chapter [not included in this extract] summarizes some of the underlying principles that we and others are utilizing to design and build new enriching and engaging environments. Although built today with the latest technological materials, these environments reproduce with great effect the best that older built environments were able to offer. We, working today, and historical architects working in centuries past, strived for the same neurological nourishment from what we build. In the past, techniques for achieving this goal were learned intuitively. Modern science is revealing the mechanisms whereby neurological nourishment acts, so that we can learn to use it in a more controlled manner. Today, we are once again aware of the physical properties and natural geometries that architects working in centuries past called upon to create the great human places we now wish to emulate.

Biophilic design’s principal contribution makes use of plants and complex natural settings as much — and as intimately — as possible in the built environment (Kellert, 2005). While our design approach does not focus specifically on the biophilic component, it supports it in a fundamental manner. By re-orienting design away from formal or ideological statements, and towards a process of optimizing neurological engagement, we are setting up the conditions for accepting biophilia. Otherwise, the conceptual distance between non-responsive architecture and the natural environment is so vast that most people simply cannot bridge the gap. We are presently living in an alternative mental universe where human creations are forever distanced from natural forms. This gap is spreading daily, as the progressive development of new technologies rewards us with useful gadgets that are increasingly “unnatural”.

To implement biophilic design, we need to create a conceptual framework based upon informational connection. This program goes against the current trends of academic specialization, since it requires the cooperation of many different disciplines. Present ways of thinking about architecture are inadequate: the representation of architectural problems has to change from an abstract domain to the natural domain dominated by human physiology and positive emotions. The forces pushing for a re-orientation necessarily come from outside architecture, and may even be resisted by architectural academia. If we are successful in this, then future architects will conceive architecture in a fundamentally different manner. 

Three Different Conceptions Of Being Human 

Biophilic design techniques depend upon the mental processes and physical mechanisms that people have evolved in response to the natural environment (Kellert, 2005). It is now necessary to consider the nature of human beings, which underpins biophilic design as a necessity and not an option. Many readers could misinterpret the biophilic focus on nature as diverting attention away from human beings themselves, even though its goal is to enhance human life on earth. This discussion is needed to prevent our work (and our colleagues’ work) from being branded as just another architectural “style” that can be applied or ignored depending on the prevailing fashion. 

We classify three fundamentally different conceptions of human nature, summarizing each of these levels in turn. In the first level, a human being is regarded as a component placed into an abstract, mechanical world. Here, human beings interact only minimally (superficially) with the natural world, a condition of being disconnected. This is an abstract conception of humanity, yet is representative of much of contemporary thinking. It is the world of the contemporary architect, in which humans participate only as sketches, intentionally blurry photos, or indistinct shadows on a computer screen. The imageability of the design is primary, with the occupant either absent or represented only symbolically. A human here is not even biological: he/she exists as an inert passenger in a fundamentally sterile and non-interactive world.

In the second level, a human being is an organism made of sensors that interact with its environment. Here, humans are biological entities: animals that possess a sensory apparatus enabling them to receive and use measurable input. This is a condition of biological connectedness to the world, i.e. situatedness (Salingaros & Masden, 2006a). In this richly biological view, a human being represents a biological system that has evolved to perceive and react with inanimate matter and especially with other organisms. Humans are considered as animals (not meant in any negative way), sharing all the evolved neural apparatus necessary to make sense of the natural world. Human modes of interaction are those we understand through nerves and sensors.

In the third level, a human being is something much more than a biological neural system. The third conception corresponds to the much older metaphysical picture of humans as spiritual beings, connected to the universe in ways that other animals are not. This is a condition of transcendental engagement with the world. The definition of human essence extends into realms more properly covered by humanistic philosophy and religion. Much of what it means to “be human” lies in this domain, and these additional qualities distinguish us from other animals. To dismiss all of this as “unscientific” would be to miss the point of humanity. In the pre-scientific ages — as for example, the Middle Ages in Europe — our conception of what we were as human beings was almost exclusively based upon insight that came from internal development. Transcendental engagement anchored our sense of self, and continues to do so for the majority of people in the developing world today. Mystical and religious, this intuitive understanding serves to tie human beings to their world in a manner independent of science. The connection, moreover, is believed to have been much stronger than the later development of a strictly scientific framework linking human beings to the rational dimension of the physical universe.

Curiously, the three levels of being human, going from detachment (disconnected), to a biological connection (situatedness), and finally to a more profound transcendental engagement, correspond to going backwards in historical time as it pertains to human existence. This seems counter-intuitive at best. If one were to reword this observation, it could be said that humankind has regressed in the depth of its connection to its surroundings (i.e. the universe) over the past decades and centuries. Just because we increased our scientific knowledge of the world, this does not guarantee that we maintain our connection to it in the human dimension. Indeed, the Cartesian method required us to detach ourselves from our world in the name of scientific enquiry, in order to be able to perform unbiased experiments. This may be fine for scientific experimentation, but it is certainly no way to maintain our human nature and to effectively operate within the world as human beings.

Level One: The Abstract Human Being 

The “modern” human being inhabits an industrialized, technological world. Since this world has become an ever vaster and encompassing machine, so too its human inhabitant has become but an ever smaller (and, by implication, less significant) component of that machine. The biological constitution of these contemporary human beings has little relevance to their situatedness in the universe: such a person could just as well be made out of metal, wires, and a minimal number of electronic sensors — a robot. The biological (not to mention the transcendental) nature of humanity is herein denied. A human being is simply a neutral cog in the machinery of the universe. It doesn’t help that contemporary physics paints precisely such a hopeless picture of cosmic irrelevance for human nature and the human spirit.

In contemporary architecture, reluctant acknowledgment is sometimes made to the genetic structure of a human being, but it is far less than would at first appear. Too often, even the most rudimentary neural capacity of humans does not enter into play when designing buildings and urban environments. Human physiological and psychological response seldom figures in design discussions today. Architects pretend to have surpassed human nature. Instead, certain formal and abstract notions about space, materials, and form are of primary concern. Those do not arise, however, from a full understanding of the processes at work that give human beings their existential foothold on earth. 

A movement to mold human beings into manipulable consumers of industrial products has been taking place for many decades. Much broader in scope than architecture and urbanism, these two disciplines have nevertheless played a significant role in an era of massive social engineering. In the drive to transform human beings into controllable objects, people’s connection to nature are suppressed. Modern individuals — at least in the more developed countries — live in a physical world defined by machines and industrial materials, and whose information fields come from media images and messages. Nature is either eliminated from the human environment, or has been relegated to a purely decorative role. Evolutionary developed sensibilities have been numbed. The world’s remaining population is no better off, because it aspires to emulate this unnatural state as a sign of progress. An automated, disconnected population is insensitive to the healing effects of natural environments.

A more benign, but nevertheless equally effective transformation led to the abstraction/mechanization of the human environment. Early 20^th-Century advances in microbiology and sanitary practices coincided with the introduction of industrial materials. A “healthy” environment became associated with a visually sterile, industrial “look” of polished metal or porcelain surfaces. For example, kitchens changed from being geometrically messy to looking like sterile factory environments; and from being made from soft and natural materials to being built using hard industrial materials (Salingaros, 2006). Plants (not to mention domestic animals) had no place there. People’s preoccupation with improved health made them suspicious of all life, not just the harmful microbes and fungi that cause disease. This was a great misunderstanding, since microbes can thrive on any surface, even ones that look sterile to the naked eye. But the clean, industrial “look” became part of our worldview, and we are still threatened by signs of life that violate it. 

This contemporary condition demonstrates that human beings can be psychologically conditioned to act against their biological nature (Hoffer, 1951; Salingaros, 2004). We are now facing a population whose sensibilities have been detached from most other life forms, and oriented principally towards an artificial world of images and machines. Explaining the benefits of biophilic design to such individuals — who no longer see relevance in real trees, animals, and ecosystems — presents a serious challenge. 

Level Two: The Biological Human Being 

We are biological creatures made of sensors that enable us to interact with our surroundings. Intelligence and consciousness are evolutionary products of our sensory systems. Up to a certain point (more than we care to admit), we share this neurological basis with other creatures of the earth (Wilson, 1978; 1984). In the past, an innate understanding of how forms, spaces, and surfaces affect us was used to design the built environment, aiming to maximize its positive effect on us. That changed when formal criteria and abstractions were introduced, replacing those of an older, humanistic architecture. By coincidence, societal discontinuities leading into the twentieth century made this replacement possible, a change which could not have taken place before then (Salingaros, 2006).

However, this does not mean that our sensory apparatus has changed in any way. We still have the same genetic structure, and our physical and psychological needs have remained the same over many millennia (Wilson, 1978; 1984). Our neurophysiologic requirements have been tempered to some extent by fashionable ideas, images, and ideologies, yet our response mechanisms still operate automatically. Therefore, we will instinctively react in a negative manner to a built environment that is neurologically non-nourishing, or which might actually cause physical anxiety and distress. It is very easy to understand the type of environment that is healthy for us — or, conversely, is unhealthy — based upon our sensory apparatus. We need only to pay heed to the signals from our own body, unencumbered by psychological conditioning.

Empirical evidence continues to accumulate towards a greater understanding of how humans operate physiologically in the built environment (Frumkin, 2001). In hospital design, the geometry of the environment plays a significant role in how long it takes for a patient to be cured. Roger Ulrich has done pioneering work in this topic (Ulrich, 1984; 2000). Surprisingly, schools do not show a strong enough interest in human physiological and psychological response to the built environment, despite decades of experimental findings on this topic. Architects instead seek greater distance and obscurity in the ethereal terrain of contemporary philosophies (Salingaros, 2004). Departments of Architecture around the world still train students in Hospital Design based on formal, stylistic ideas of spaces and materials, not paying attention to Ulrich’s work.

Our eye/brain system has evolved to perceive fine detail, contrast, symmetries, color, and connections. Symmetry, visual connections, ornament, and fine detail are necessary on buildings; not for any stylistic reason, but because our perception is built to engage with those features (Enquist & Arak, 1994; Salingaros, 2003; 2006). The physiological basis for sensory experience is the ultimate source of our being, which thus relies strongly on certain geometric elements to which we connect. Creating an environment that deliberately eschews these elements (visual elements which are found in nature and in all traditional architectures) has negative consequences for our physiology, and thus for our mental health and sense of wellbeing (Joye, 2006; 2007a; 2007b; Kellert, 2005). 

Environments devoid of neurologically-nourishing information mimic signs of human pathology. For example, colorless, drab, minimalist surfaces and spaces reproduce clinical symptoms of macular degeneration, stroke, cerebral achromatopsia, and visual agnosia (Salingaros, 2003; 2006). We feel anxious in such environments, because they provoke in us a similar sensation as sensory deprivation and neurophysiologic breakdown. It is curious that architectural design in the past several decades incorporated more and more such alarming elements and devices as part of its stylistic vocabulary. Some architectural critics attempt to portray those in a positive light using seductive images, and defend them by employing specious references to technological progress (Salingaros, 2004). 

The discipline of Environmental Psychology actually began in faculties of architecture, as a natural investigation of how built environments were affecting people. As soon as the first results (several decades ago) indicated that some of the most fashionable contemporary architectural and urban typologies, spaces, and surfaces might in fact be generating physiological and psychological anxiety in their users, fellow architects lost interest. Environmental Psychologists moved (or were systematically relocated) outside architectural academia, into Departments of Psychology, which is where they can be found today. 

Ironically, to understand the environmental aspect better, we turn to studies on higher mammals. Judith Heerwagen has studied zoo animal behavior in naturalistic versus more artificial environments (Heerwagen, 2005). Starting from substantial observations of zoo animals, she reports the results of implementing a transformation towards more naturalistic habitats. As a consequence, the animals’ psychological and social well-being has been drastically improved. Zoo animals kept in drab, monotonous, and minimalist environments (i.e. those that we humans also perceive as boring and depressing) exhibited neurotic, aberrant, and antisocial behavior never observed in the wild. Moved to more naturalistic and stimulating habitats, the animals returned to more normal, healthier behavior patterns. 

This body of results has dramatic implication for our children. Evidence has been accumulating since the 1960s that complexity and stimulation in the environment can lead to increased intelligence of a developing animal. Incontrovertible results are obtained with young rats raised in information-rich environments, whose brains increase in size, and can improve their neural connectivity by up to 20% (Squire & Kandel, 1999: page 200). This represents much more than just an anatomical change in the brain, because it optimizes the cortical physiology responsible for intelligence. Those rats raised in enriched environments are then observed to do much better in intelligence tests (such as solving complex maze problems) and training. We interpret this result as the fulfillment of a necessary external component in the brain’s development. It also raises questions of collective culpability for neglecting or minimizing neurological connective structure. 

We need to point out the importance of relying on clinical studies rather than on surveys. Many studies recording user preferences have been done over decades, some of them uncovering the advantages of natural environments, and of environments mimicking those geometrical qualities (Joye, 2006; 2007a; 2007b; Kellert, 2005; Kellert & Wilson, 1993). Nevertheless, a large number of those studies showed only moderate preferences, or were inconclusive. A recent experiment raises the possibility that those earlier results may in fact reflect conditioned response. In a clinical comparison of two distinct environments, one a plain room, and the other with wooden beams added to create hierarchical scaling, the subjects did not express any preference. Yet the physiological monitors recorded a marked response in favor of the room with hierarchical subdivisions and natural detail (Tsunetsugu, Miyazaki & Sato, 2005). We (and the study’s authors) conclude that physiological effects of the environment cannot always be consciously recognized.