Navigation, such as the choice of a pedestrian to turn to the right or left, is typically modeled as a complex perceptual and cognitive activity that requires an intricate integration of current and past stimuli (Cuqlock-Knopp & Whitaker, 1993). Even with such complex processing, however, sometimes simple asymmetries emerge that reliably affect behavior. In the present work we examine the tendency for pedestrians to favor a left or right turning direction.
Nearly 70 years ago, Robinson (1933) reported that museum patrons have a strong tendency to bear to the right upon entering a gallery (75%). Robinson stated that this trend had been observed across many American museums, even in the presence of signs directing visitors to the opposite direction. In contrast, he indicated that curators were more likely to plan displays beginning on the left, using blueprint plans that move from left to right, as with English-language written text.
Robinson (1933) stated that his data were obtained from experimental observation, but he explained little about his methodology. He indicated that curators seemed to be influenced by the directionality imposed by written language, but he did not hypothesize any source for the museum patron's turning bias.
Several early researchers found that the paths taken by persons when walking a straight line blindfolded tend to veer to the right (Blumenthal, 1928; Brigden, 1935; Claparede, 1942, as cited in Howard & Templeton, 1966; Lund, 1930; Szymanski, 1913). However, some of these findings have speculative statistical significance and are controversial. Lenkner (1934) even found evidence of movement in the opposite direction. In trying to explain Szymanski's finding that people veer to the right, Schaeffer (1928) posited a spiraling mechanism common to most animals that functions without regard to handedness or other physical characteristics. Lund (1930) suggested that path curvature is correlated with differences in leg length.
Although these findings are interesting, the average difference in leg length that he found was small (5 mm), and the shorter leg was almost as likely to be on the left side as on the right. None of these early studies more globally examined possible reasons for a turning bias in locomotion or navigation. The goals in the present study are to test Robinson's (1933) findings and investigate possible sources of any bias to turn right.
Why should laterality bias be studied? In general, humans and animals are anatomically symmetric: two arms, two legs, two eyes, and two brain hemispheres. Humans find symmetry more aesthetically pleasing and possess a natural bias to perceive objects as symmetric (McBeath, Schiano, & Tversky, 1997). However, in most cases of symmetry there are often instances of functional asymmetries. The steering wheel inside a car is offset to one side, the human heart is similarly offset, and even faces often exhibit salient local asymmetries (Sackeim, Gur, & Saucy, 1978). External symmetry is advantageous for aerodynamic reasons, but presumably pressures for specialization would also promote notable asymmetries. For example, it is thought that the differential specialization of the two hemispheres of the brain is the source of the increased cognitive ability of humans (Bryden, 1986; Levy, 1985). Lateral specialization is not unique to the human species; it exists in animals as well (Corballis, 1983). Lateralization seems to account for physiological factors such as handedness and eye dominance, and it might even be a factor in external behaviors such as locomotion and direction of navigation.
Lateralization could lead to a locomotive directional bias, which may be especially important when sources of information are degraded or limited, as occurs, for example, with older drivers (Maltz & Shinar, 1999). …