In the past, gift-giving has interested mainly anthropologists because it was taken to be a primitive mode of exchange. Recent contributions of economists acknowledge however that gift-giving is still present in modern exchange economies. In this paper gifts are characterized by motivations. Two main features of gift giving are to be explained: (in-)adequacy and (non-)reciprocity. It is argued ...

We demonstrate that a simple model, constructed on the premise that people are motivated by both their pecuniary payoff and their relative payoff standing, explains behavior in a wide variety of laboratory games. Included are games where equity is thought to be a factor, such as ultimatum, two-period alternating offer, and dictator games; games where reciprocity is thought to play a role, such ...

The phenomenon of change blindness has received a great deal of attention during the last decade, but very few experiments have examined the effects of the subjective importance of the visual stimuli under study. We have addressed this question in a series of studies by introducing choice as a critical variable in change detection (see Johansson, Hall, Sikström, & Olsson, 2005, Johansson, Hall,...

The vertical-horizontal illusion is the tendency for observers to overestimate the length of a vertical line relative to a horizontal line that has the same length. One explanation of this illusion is that the visual field is elongated in the horizontal direction, and that the vertical-horizontal illusion is a kind of framing effect (Künnapas, 1957a, 1957b, 1957c). Since the monocular visual fi...

The present study examined the degree to which positive illusion is associated with sport performance in basketball players among 3 different cultures: The United States of America, Croatia, and Norway. Positive illusion is a cognitive characteristic that is common in mentally healthy individuals, and becomes especially important in the athletic arena. The model tested in this study depicts the...

As virtual environment (VE) technology has become more disseminated, harmful physiological influences on users of VE have been reported such as simulator sickness and motion sickness -collectively called VE sickness. For VE safety and comfort, we note a new dynamic visual illusion, called" rotational dynamic illusion" .Several psychophysical experiments measuring head movement in illusion obser...

When two identical faces are aligned vertically, humans readily perceive the face at the bottom to be fatter than the top one. This phenomenon is called the fat face illusion. Furthermore, an apparent similarity has been pointed out between the fat face illusion and the Jastrow illusion. Recent studies have suggested the importance of facial contours and the role of basic-level processing of fa...

The Pinna illusion (Pinna & Brelstaff, 2000) consists of two concentric rings of micropatterns that appear to counter-rotate when the observer moves towards the stimulus. There have been several reports that the illusion is stronger when the retinal expansion is produced by observer self-motion than when produced on a computer screen without observer self-motion. In fact, we found that the illu...

The Rotating Snakes Illusion employs patterns with repetitive asymmetric luminance steps forming a "snake wheel." In the underlying luminance sequence {black, dark grey, white, light grey}, coded as {0, g1, 100, g2}, we varied g1 and g2 and measured illusion strength via nulling: Saccades were performed next to a "snake wheel" that rotated physically; observers adjusted rotation until a station...

Amblyopia ("lazy eye") is an impairment in visual acuity resulting from abnormal neural development in the visual cortex. We tested the responses of ten amblyopic and six normal observers to illusions of perceived orientation in textures of Gabor patches: the "Fraser illusion," the "phase illusion," and a "tilted chain" illusion. The illusory tilt of the stimulus rows was matched by actual tilt...