Illusions in modal reasoning

According to the mental model theory, models represent what is true, but not what is false. One unexpected consequence is that certain inferences should have compelling, but invalid, conclusions. Three experiments corroborated the occurrence of such illusions in reasoning about possibilities. When problems had the heading "Only one of the premises is true," the participants considered the truth of each premise in turn, but neglected the fact that when one premise is true, the others are false. When two-premise problems had the heading "One of the premises is true and one is false," the participants still neglected the falsity of one of the premises. As predicted, however, the illusions were reduced when reasoners were told to check their conclusions against the constraint that only one of the premises was true. We discuss alternative explanations for illusory inferences and their implications for current theories of reasoning.     

Illusions prepared as stereograms

The loci of organization and the modes of operation of certain perceptual mechanisms may be determined by presenting appropriate stimuli independently to each eye in such a way that they become superimposed in stereoscopic vision. It is possible that understanding of the mechanisms responsible for the appearance of certain “geometrical illusions” may be furthered by adopting this procedure. The two functional components of a sample of illusions are distinguished and illustrated in the form of stereograms.     

Illusions of bent line

A recent paper offered an explanation of the Poggendorf illusion, assuming that it results from a failure of the visual system to make a perfect resolution of acute angles. Variations of the illusion were drawn eliminating all acute angles, and the illusion was shown to remain in full strength. A variation of the figure preserving the acute angle was drawn, and the illusion was found to reverse in direction. Several theoretical interpretations are considered but none accepted, and it is concluded that the illusion remains unexplained.     

Illusions of size change in dynamic displays

A line of constant width viewed against an expanding or contracting grating appears to become narrower or wider, respectively. This effect was studied using a computer-controlled video system with a motorized zoom lens. The magnitude of the illusory size (width) change with a vertical line did not differ when viewed against a horizontal or an oblique background, and the size change was not due to static size contrast between the line and the background. The illusory narrowing observed with an expanding background was equivalent to the widening observed with a contracting background. The apparent change in the width of lines that actually expanded was consistently underestimated, either on a similarly changing background or when viewed against a gray field. Although the transformation of the background and line produced changes in their perceived distance, this did not occur for a constant line against a transforming background, even though this condition induced the perceived size change.     

Illusions and Knowing What Is Real

Geometrical illusions are displays that give false impressions that observers take to be accurate. They have traditionally been cited as evidence against the naive realist claim that people see the world as it "really" is. Such illusions, however, often depend on their being viewed from a single vantage point (Kennedy & Portal, 1990). In Gibsonian terms, they depend on the availability of impoverished information. In this study, spatial transformations were applied to line-length (Sander parallelogram) and area (Jastrow curves) illusions to provide information to observers about veridical size. In particular, the reversal of certain parts of the displays resulted in informative invariants that specified the veridical nature of the parts. Most observers were able to use the information.     

Narcissistic Illusions in Self-Evaluations of Intelligence and Attractiveness

In this study we compared the ability of narcissism and self-esteem to predict positive illusions in self-evaluations of intelligence and physical attractiveness in a sample of 146 college students. Narcissism predicted both types of illusion for males and females; self-esteem predicted intelligence self-illusion for males. Both males and females overestimated their own intelligence, with males, but not females, also overestimating their attractiveness. Positive illusions for intelligence and attractiveness were correlated. Males showed greater positive illusions than females, with this effect at least partly attributable to observed gender differences in narcissism.     

Age-Related Differences in Memory Illusions: Revelation Effect

Older adults are often more susceptible to various illusions and distortions of memory than young adults. In the experiments reported here, we explored the question of whether normal aging was associated with a larger revelation effect, an illusion of memory in which items that are revealed gradually during a recognition test are more likely to be called old than unrevealed items that are shown in their entirety. Contrary to expectations, older adults were not susceptible to this memory illusion. A revelation effect occurred for young but not older adults, even when older adults were similar to young adults on measures of recognition and repetition priming. When data across experiments were combined, there was evidence for a negative revelation effect in older adults in which revealed items were less likely called old than unrevealed items. These results place boundary conditions on the claim that older adults are more susceptible than young adults to memory illusions, and imply that one or more mechanisms underlying the revelation effect are age sensitive.     

Speciesism,Arbitrariness and Moral Illusions

Philosophia - Just as one line appears to be longer than another in an optical illusion, we can have a spontaneous moral judgment that one individual is more important than another. Sometimes such...