The individual always attempts schema identification based on available cues, whether or not those cues are sufficient for unique identification. In such cases the subconscious supplies the answer that seems most plausible in the current environment. Ittelson and Kilpatrick [1951] argue persuasively that optical illusions are simply a readily investigated aspect of the much broader phenomenon of subconsciously probabilistic schema identification.
“Resulting perceptions are not absolute revelations of ‘what is out there’ but are in the nature of probabilities or predictions based on past experience. These predictions are not always reliable, as the [optical illusion] demonstrations make clear.” [Ittelson and Kilpatrick, 1951]
“Perception is not determined simply by the stimulus patterns; rather it is a dynamic searching for the best interpretation of the available data. . . Perception involves going beyond the immediately given evidence of the senses: this evidence is assessed on many grounds and generally we make the best bet. . . Indeed, we may say that a perceived object is a hypothesis, suggested and tested by sensory data.” [Gregory, 1966]
No wonder expectations affect our observations! With a perceptual system geared to understanding the present by matching it to previous experience, of course we are prone to see what we expect to see, overlook anomalies, and find that evidence confirms our beliefs (Figure 22). Remarkably, the scientist’s propensity for identifying familiar patterns is combined with a hunger for discovering new patterns. For the fallible internal photographer, it doesn’t matter whether the spectacle is the expansion of the universe or the fate of a bug:
“So much of the fascinating insect activity around escapes me. No matter how much I see, I miss far more. Under my feet, in front of my eyes, at my very finger’s end, events are transpiring of fascinating interest, if I but knew enough or was fortunate enough to see them. If the world is dull, it is because we are blind and deaf and dumb; because we know too little to sense the drama around us.” [Fabre, cited by Teale, 1959]
Postmodernism
“Science is a social phenomenon. . . It progresses by hunch, vision, and intuition. Much of its change through time is not a closer approach to absolute truth, but the alteration of cultural contexts that influence it. Facts are not pure information; culture also influences what we see and how we see it. Theories are not inexorable deductions from facts; most rely on imagination, which is cultural.” [Gould, 1981]
In the mid-twentieth century, the arts were dominated by modernism, which emphasized form and technique. Many people thought modernism was excessively restrictive. In reaction, the postmodern movement was born in the 1960’s, embracing a freedom and diversity of styles. Postmodern thinking abandoned the primacy of linear, goal-oriented behavior and adopted a more empathetic, multipath approach that valued diverse ethnic and cultural perspectives. Postmodernism encompassed the social movements of religious and ethnic groups, feminists, and gays, promoting pluralism of personal realities.
According to the postmodern critique, objective truth is a dangerous illusion, developed by a cultural ‘elite’ but sold as a valid multicultural description. Cultural influences are so pervasive that truth, definite knowledge, and objectivity are unobtainable. Consequently, we should qualify all
