Public Places and Private Spaces: The Psychology of Work, Play, and Living Environments

Stimulus load is Mehrabian's term for the total information rate an environment presents across all sensory channels—spatial complexity, color intensity, sound level, social density, novelty, and motion. Rather than analyzing each environmental feature separately, the book proposes that load provides a single dimension for comparing a cocktail party to a prison cell, a library to a sports arena. Kirkus Reviews summarized the framework as analyzing environments for 'qualities such as uncertainty, density, novelty, motion and contrast.' The load concept enables Mehrabian to argue that adding stimuli to a pleasant environment improves experience while adding them to an unpleasant one worsens it, producing the U-shaped response curve he describes.

Mehrabian argues that people differ in how they process environmental stimuli. Nonscreeners 'tend to hear, see, smell, and sense more than screeners,' experiencing places as more complex and loaded, staying aroused longer in high-load situations. Screeners are more selective, reducing load by allocating less importance to environmental parts, recovering equilibrium more quickly. A Geographical Review critique noted Mehrabian 'simply dichotomizes humans' rather than treating screening as a continuum, and did little to investigate why the trait exists. The distinction matters because it implies that identical environments will produce opposite responses in different people—a cafeteria that energizes one worker may exhaust another.

Reviews consistently praised the scope while questioning the rigor. Kirkus called it 'lively' but noted it 'suffers from length and overinclusiveness.' A Geographical Review critic wrote that Mehrabian 'sacrifices depth for breadth' in appealing to a popular market, and that his loose handling of 'environment'—extending it to drugs and music—was 'unsettling and misleading.' A Journal of Applied Communication Research review found the book lacked 'a unified presentation' and that environments were not 'delineated in an organized manner.' The common thread: the book successfully demonstrated the range of environmental psychology's applicability but did not fully deliver the systematic theory its framework promised.

The book's 30 chapters are organized into seven parts: Basics, Intimate Environments, Residential Environments, Work Environments, Therapeutic Environments, Play Environments, and Communal Environments. Specific settings include homes, apartments, public housing, factories, offices, schools, libraries, health spas, mental hospitals, prisons, movie theaters, museums, bars, restaurants, sports arenas, stores, dormitories, retirement communities, suburbs, and cities. The first section establishes the PAD framework and stimulus load; subsequent sections apply it. A Journal of Applied Communication Research reviewer found the work environment section—particularly the analysis of office 'cabbage patch' layouts—the most credible part of the book.

The most substantive critique concerned the book's failure to account for human intentionality and active structuring of experience. A Geographical Review review argued that Mehrabian 'still describes person-environment relations in terms of approach and avoidance as if the environment were "out there,"' neglecting 'the intent that humans bring to a situation or the role of planning and the active structuring of our behavior.' The reviewer also noted Mehrabian's optimism about predicting responses to environments was unwarranted given this omission. The book presents environments as stimuli acting on passive recipients, which critics found insufficient for a complete environmental psychology.

Public Places and Private Spaces applies the theoretical framework developed in the 1974 volume to a wide range of concrete settings. An Approach to Environmental Psychology established the pleasure-arousal-dominance model and information rate as abstract concepts; the 1976 book translates them into accessible analyses of specific places—offices, prisons, museums, suburbs—for a general readership. The later book is less technical and more prescriptive, offering design suggestions rather than purely theoretical exposition. In effect, Public Places and Private Spaces is the popular application of the research program the earlier book established, extending the PAD framework from laboratory findings to everyday environmental experience.