This study investigates the effects of familiarity and the size of a novel object on perception of depth. Familiar size is a visual depth cue that provides information about the distance of an object. This project explores if the familiar size illusion is a result of an automatic perceptual process or an intellectual thought process. This data was collected in two phases, a familiarization phase and a testing phase. The experimental participants were familiarized for 30 seconds with a novel object, while the control group was not shown any objects prior to presentation of test objects. The novel test stimuli were constructed in 5 sizes and participants in the familiar group were familiarized with the medium size object. Participants were then asked to indicate the perceived distance of different sized objects by moving a rod with a pointer at the end to match the distance. The smaller comparison objects subtended visual angles that participants had not previously experienced, while larger comparison objects produced a larger visual angle than the participants had seen during the familiarization phase. The testing phase was identical for both familiar and unfamiliar control groups. Apparent distance was influenced by the size of the objects. Larger objects were judged to be closer than the smaller objects. Participants not familiarized showed smaller effects of stimulus size than the familiarized group. The effect of familiarity was not significant for the smaller stimuli but was very significant for the larger stimuli. The results were not consistent with the cognitive theory which argues that familiar size is a result of a conscious thought process. These outcomes are predicted under the model of familiar size being an automatic perceptual process.

This study examines pedestrian walking-side bias in America. We recorded the walking behavior of 430 pedestrian groups and analyzed the left-vs-right passing response around either a stationary obstacle or other oncoming pedestrians. Past research indicates about two-thirds of American pedestrian’s favor walking on the right side of a centrally located inanimate object. We test if this lateral bias is larger for interactions between bypassing people in larger group sizes. We tested two principal hypotheses: H1: Overall, pedestrians will exhibit a right-side passing bias, and H2: The magnitude of the right-side passing bias will increase as a function of group size. Our findings confirm H1: We found a reliable right-side pedestrian bias when pedestrians pass either an inanimate object or other people, a percentage that is similar to past findings. We also confirmed H2: when passing people but not obstacles. When individuals of groups pass other people, biases are additive, with the right-side lateral walking bias increasing by about 10% per additional pedestrian, reaching a ceiling of about 95% rightward paths for groups of five or more. In general, the right-side lateral walking-bias appears to be a prototypical example of a socially trained natural regularity that is readily modified by situational contexts. Findings from this study confirm that small individual biases accumulate into larger biases in groups, a principle that likely has wide ranging generalizability relevant to both the design of locomotive spaces as well as group dynamics in other more abstract socio-relational domains such as political views and prejudice.