What hands know about objects; taking perception of hills out of context: A response to Durgin (2013)

In a recent paper, we provided independent evidence on the accuracy of ‘haptically’ measured geographical slant perception (Taylor-Covill & Eves, 2013). Durgin (2013) argues that the devices used in our work, namely the palm-board, and palm-controlled inclinometer (PCI), are not measures of perception. In response, we outline four failures of replication in the laboratory work of Durgin and colleagues on which they base their model of slant perception. We also highlight fundamental differences between the perceptual tasks Durgin and colleagues ask of participants relative to those of Proffitt and colleagues' traditional measures. These subtle differences might help explain how the two groups have arrived at discrepant conclusions.     

Summarizing slant perception with words and hands; an empirical alternative to correlations in Shaffer,McManama, Swank,Williams & Durgin (2014)

The paper by Shaffer, McManama, Swank, Williams & Durgin (2014) uses correlations between palm-board and verbal estimates of geographical slant to argue against dissociation of the two measures. This paper reports the correlations between the verbal, visual and palm-board measures of geographical slant used by Proffitt and co-workers as a counterpoint to the analyses presented by Shaffer and colleagues. The data are for slant perception of staircases in a station (N = 269), a shopping mall (N = 229) and a civic square (N = 109). In all three studies, modest correlations between the palm-board matches and the verbal reports were obtained. Multiple-regression analyses of potential contributors to verbal reports, however, indicated no unique association between verbal and palm-board measures. Data from three further studies (combined N = 528) also show no evidence of any relationship. Shared method variance between visual and palm-board matches could account for the modest association between palm-boards and verbal reports.     

Explicit and motoric dependent measures of geographical slant are dissociable: A reassessment of the findings of Durgin, Hajnal, Li, Tonge, and Stigliani (2010)

Durgin et al. (2010) argued that the apparent accuracy of the palmboard measure of geographical slant is accidental and reflects limitations in wrist flexion that reduce palmboard adjustments by just the right amount given the perceptual overestimations upon which they are based. This account is inconsistent with findings that verbal reports and palmboard adjustments are dissociable. In addition to previous evidence found for such dissociation, Durgin et al. also found verbal/palmboard dissociations in Experiment 2. Experiments 1 and 3 of Durgin et al. lacked verbal reports and instead compared palmboard adjustments to free-hand estimates in the context of small wooden surfaces. These experiments are not relevant to the issue of verbal/palmboard dissociability. Across studies, the accuracy of Durgin et al.'s palmboard implementation is far less than that found by others (Feresin & Agostini, 2007). The design of Durgin et al.'s Experiment 5 misrepresented the experimental conditions of Creem and Proffitt (1998), and consequently, the findings of this study have no bearing on the issue at hand.     

Is there any Proffitt in stair climbing? A headcount of studies testing for demographic differences in choice of stairs

The apparent slope of a hill, termed geographical slant perception, is overestimated in explicit awareness. Proffitt (2006) argued that overestimation allows individuals to manage their locomotor resources. Increasing age, fatigue, and wearing a heavy back pack will reduce the available resources and result in steeper reports for a particular hill. In contrast, Durgin and colleagues have proposed an alternative explanation for these effects based on experimental design—particularly, the potential effects of experimental demand. Proffitt’s resource-based model would predict that pedestrians with reduced resources should avoid climbing a hill that would further deplete their resources if the opportunity arose. Within the built environment, stairs are the man-made equivalent of relatively steep hills (20°–30°). In many public access settings, pedestrians can avoid climbing the stairs by opting for an adjacent escalator. Observations of pedestrian behavior in shopping malls reveal that 94.5 % do so. This article summarizes the effects of demographic grouping on avoidance of stairs in public health research. Observations in shopping malls (n = 355,069) and travel contexts (n = 711,867) provide data consistent with Proffitt’s resource model. Women, the old, and those carrying excess body weight or large bags avoid the stairs more than do their comparison groups. Discussion focuses on differences in physiology that may underlie avoidance of stair climbing in order to highlight the pedestrian behavior that psychology needs to explain.     

An effect of mood on the perception of geographical slant

Previous research has shown that hills appear steeper to those who are fatigued, encumbered, of low physical fitness, elderly, or in declining health (Bhalla & Proffitt, 1999; Proffitt, Bhalla, Gossweiler, & Midgett, 1995). The prevailing interpretation of this research is that observers' perceptions of the environment are influenced by their capacity to navigate that environment. The current studies extend this programme by investigating more subtle embodied effects on perception of slant; namely those of mood. In two studies, with two different mood manipulations, and two estimates of slant in each, observers in a sad mood reported hills to be steeper. These results support the role of mood and motivational factors in influencing spatial perception, adding to the previous work showing that energetic potential can influence perception.     

An effect of mood on the perception of geographical slant

Previous research has shown that hills appear steeper to those who are fatigued, encumbered, of low physical fitness, elderly, or in declining health (Bhalla & Proffitt, 1999; Proffitt, Bhalla, Gossweiler, & Midgett, 1995). The prevailing interpretation of this research is that observers’ perceptions of the environment are influenced by their capacity to navigate that environment. The current studies extend this programme by investigating more subtle embodied effects on perception of slant; namely those of mood. In two studies, with two different mood manipulations, and two estimates of slant in each, observers in a sad mood reported hills to be steeper. These results support the role of mood and motivational factors in influencing spatial perception, adding to the previous work showing that energetic potential can influence perception.     

Perceiving virtual geographical slant: action influences perception

In 4 experiments, the authors varied the extent and nature of participant movement in a virtual environment to examine the influence of action on estimates of geographical slant. Previous studies showed that people consciously overestimate hill slant but can still accurately guide an action toward the hill (D. R. Proffitt, M. Bhalla, R. Gossweiler, & J. Midgett, 1995). Related studies suggest that one's potential to act may influence perception of slant and that distinct representations may independently inform perceptual and motoric responses. The authors found that in all conditions, perceptual judgments were overestimated and motoric adjustments were more accurate. The virtual environment allowed manipulation of the effort required to walk up simulated hills. Walking with the effort appropriate to the visual slant led to increased perceptual overestimation of slant compared with active walking with the effort appropriate to level ground, while visually guided actions remained accurate.     

Design,data, and theory regarding a digital hand inclinometer: a portable device for studying slant perception

Palm boards are often used as a nonverbal measure in human slant perception studies. It was recently found that palm boards are biased and relatively insensitive measures, and that an unrestricted hand gesture provides a more sensitive response (Durgin, Hajnal, Li, Tonge, & Stigliani, Acta Psychologica, 134, 182-197, 2010a). In this article, we describe an original design for a portable lightweight digital device for measuring hand orientation. This device is microcontroller-based and uses a micro inclinometer chip as its inclination sensor. The parts are fairly inexpensive. This device, used to measure hand orientation, provides a sensitive nonverbal method for studying slant perception, which can be used in both indoor and outdoor environments. We present data comparing the use of a free hand to palm-board and verbal measures for surfaces within reach and explain how to interpret free-hand measures for outdoor hills.     

An imputed dissociation might be an artifact: Further evidence for the generalizability of the observations of Durgin et al. 2010

We recently showed that palm board measures are systematically inaccurate for full-cue surfaces within reach of one's hand, whereas free-hand gestures and reaching actions are quite accurate for such surfaces (Durgin, Hajnal, Li, Tonge, & Stigliani, 2010). Proffitt and Zadra (2010) claim that our demonstration that palm boards are highly inaccurate is irrelevant to interpreting past and present findings concerning dissociations between verbal reports and palm board estimates. In their paper they offer a theoretical representation of the findings of Bhalla and Proffitt (1999) and argue that our analysis is incompatible with their account. We offer here an alternative account of the findings of Bhalla and Proffitt, based on their actual data (which are fully compatible with our original analysis). We further show how our account generalizes to more recent studies that continue (1) to mistakenly describe null statistical effects on (insensitive) palm boards as evidence of a “dissociation” from (more sensitive) verbal measures that show a similar relative magnitude of change and (2) to introduce uncontrolled demand characteristics.     

Affordances matter in geographical slant perception

We argue that the experimental conditions in the Durgin et al. (2009) study were so different from those in Bhalla and Proffitt (1999) that the results of the former study cannot be generalized to the latter. The participants in the Durgin et al. study viewed a 2-m-long ramp; those in Bhalla and Proffitt viewed expansive hills. When drawing generalizations from one study to another, equating experimental conditions is always important; moreover, from an embodied perspective on perception, equating the opportunities for action also matters.     

Palm boards are not action measures: An alternative to the two-systems theory of geographical slant perception

Whereas most reports of the perception of outdoor hills demonstrate dramatic overestimation, estimates made by adjusting a palm board are much closer to the true hill orientation. We test the dominant hypothesis that palm board accuracy is related to the need for motor action to be accurately guided and conclude instead that the perceptual experience of palm-board orientation is biased and variable due to poorly calibrated proprioception of wrist flexion. Experiments 1 and 3 show that wrist-flexion palm boards grossly underestimate the orientations of near, reachable surfaces whereas gesturing with a free hand is fairly accurate. Experiment 2 shows that palm board estimates are much lower than free hand estimates for an outdoor hill as well. Experiments 4 shows that wrist flexion is biased and noisy compared to elbow flexion, while Experiment 5 shows that small changes in palm board height produce large changes in palm board estimates. Together, these studies suggest that palm boards are biased and insensitive measures. The existing literature arguing that there are two systems in the perception of geographical slant is re-evaluated, and a new theoretical framework is proposed in which a single exaggerated representation of ground-surface orientation guides both action and perception.     

Impressions of World of Warcraft players’ personalities based on their usernames: Interobserver consensus but no accuracy

Millions of people interact in the context of massively-multi-player-online-role-play-games (MMORPGs). Here we address whether MMORPG usernames convey accurate information about users’ personalities. Impressions based on email addresses show some accuracy but MMORPG’s are different because they provide little accountability, with little expectation that users will ever meet in person. We assessed consensus and accuracy in impressions based on 1357 (153 females) World of Warcraft users. Ratings of the usernames in terms of the Big Five dimensions yielded strong consensus (mean ICC = .46) but low accuracy (mean r = .01). Lens-model analysis suggest that features of the usernames have little validity, but observers used them anyway. Discussion focuses on why results might differ from those based on email addresses.     

What do hands know about hills? Interpreting Taylor-Covill and Eves (2013) in context

Hills appear much steeper than they are. Although near surface slant is also exaggerated, near surfaces appear much shallower than equivalently slanted hills. Taylor-Covill and Eves (2013) propose a new type of palm orientation measuring device that provides outputs that accurately reflect the physical slants of stairs and hills from 19 to 30° and also seems to accurately reflect the slants of near surfaces (25–30°). They question the validity of the observations of Durgin, Hajnal, Li, Tonge & Stigliani (2010), who observed that palm boards grossly underestimated near surfaces. Here I review our recent work on the visual and haptic perception of near surface orientation in order to place Taylor-Covill and Eves' arguments in context. I note in particular that free hand measures of real surfaces in near space show excellent calibration, but free hand measures show gross exaggeration for hills. This leads to the question of the grounds for preferring a mechanical device to a freely wielded hand. In addition I report an investigative replication of the crucial observations that led to our concerns about the value of palm boards as measures of perception and note the specific methodological details that we have accounted for in our procedures. Finally, I propose some testable hypotheses regarding how better-than-expected haptic matches to hills may arise.     

Deontic and epistemic reasoning in children

It is widely accepted that adults show an advantage for deontic over epistemic reasoning. Two published studies (Cummins, 1996b; Harris and Núñez, 1996, Experiment 4) found evidence of this “deontic advantage” in preschool-aged children and are frequently cited as evidence that preschoolers show the same deontic advantage as adults. However, neither study has been replicated, and it is not clear from either study that preschoolers were showing the deontic advantage under the same conditions as adults. The current research investigated these issues. Experiment 1 attempted to replicate both Cummins’s and Harris and Núñez’s studies with 3- and 4-year-olds (N = 56), replicating the former with 4-year-olds and the latter with both 3- and 4-year-olds. Experiment 2 modified Cummins’s task to remove the contextual differences between conditions, making it more similar to adult tasks, finding that 4-year-olds (n = 16) show no evidence of the deontic advantage when no authority figure is present in the deontic condition, whereas both 7-year-olds (n = 16) and adults (n = 28) do. Experiment 3 removed the authority figure from the deontic condition in Harris and Núñez’s task, again finding that 3- and 4-year-olds (N = 28) show no evidence of the deontic advantage under these conditions. These results suggest that for preschoolers, the deontic advantage is reliant on particular contextual cues such as the presence of an authority figure, in the deontic condition. By 7 years of age, however, children are reasoning like adults and show evidence of the advantage when no such contextual cues are present.     

A protean approach to social influence: Dark Triad personalities and social influence tactics

To avoid detection, those high on Dark Triad traits (i.e., narcissism, psychopathy, and Machiavellianism) may adopt a protean approach to interpersonal influence. We show the Dark Triad traits correlate with a number of unique tactics of influence (Study 1; N = 259). We show this protean approach was insensitive to differences in targets of manipulation (Study 2; N = 296). When forced to choose one tactic to solve different adaptive problems, the Dark Triad traits were correlated with unique tactical choices (Study 3; N = 268). We show these associations are generally robust to controlling for the Big Five and participants’ sex (Study 1 and 2). We discuss the theoretical implications of these findings for both life history and cheater-detection theories.     

Digit ratio (2D:4D) and sex-role orientation: Further evidence and meta-analysis

Three new studies (N = 132, 623, 1112) did not yield hypothesized associations between digit ratio (2D:4D), an assumed negative correlate of prenatal testosterone, and psychometrically measured sex-role orientation (positive association with femininity, negative ones with masculinity and masculinity-femininity difference scores) among heterosexuals of either sex. Meta-analysis of the pertinent literature (N = 6311, 28 studies from 10 countries, 46% unpublished) showed only men’s (but not women’s) left-hand (but not right-hand) 2D:4D reliably related as expected (positively) to femininity. This effect was tiny (0.14% attributable variance) and possibly non-robust (crucially dependent on one large study included). Hence, the cumulative evidence does not support systematic, robust, noteworthy within-sex correlations between 2D:4D and the masculinity/femininity personality dimensions.     

Skating down a steeper slope: fear influences the perception of geographical slant

Previous studies have shown that conscious awareness of hill slant is overestimated, but visually guided actions directed at hills are relatively accurate. Also, steep hills are consciously estimated to be steeper from the top than the bottom, possibly because they are dangerous to descend. In the present study, participants stood at the top of a hill either on a skateboard or a wooden box of the same height. They gave three estimates of the slant: a verbal report, a visually matched estimate, and a visually guided action. Fear of descending the hill was also assessed. Those participants who were scared (by the skateboard) consciously judged the hill to be steeper than unafraid participants. However, the visually guided action measure was accurate across conditions. These results suggest that explicit awareness of slant is influenced by the fear associated with a potentially dangerous action that could be performed on the hill.     

Coordination dynamics of elliptic shape drawing: effects of orientation and eccentricity

The aim of the present study was to show the effect of orientation on producing ellipses of various eccentricities. Ten right-handed adults were required to reproduce eight series of 84 ellipses on a graphic tablet at spontaneous speed. The ellipses displayed seven eccentricities, corresponding to the Lissajous plot produced by two orthogonal harmonic oscillators whose relative phase (RP) varied from 0° (a line) to 90° (a circle), and twelve orientations, the long axis of the ellipses aligned in a direction ranging from three to nine o’clock with respect to the body transverse plane. Results confirmed the participant’s preference for two eccentricities, 0° and 45°, that is, a line and an ellipse of intermediate eccentricity, respectively. Except for the circle, insensitive to orientation by definition, orientation became a cogent constraint: In the 10:30 o’clock direction, line drawing (0° RP) increased in variability and the intermediate ellipse (45° RP) was attracted towards a circle (90° RP). These findings suggest an interaction between orientation effects, putatively due to differences in the motion of the wrist and fingers, and eccentricity effects, which may pertain to preferences arising from the non-linear coupling between the effectors.     

Partners’ Attributions for Service Members’ Symptoms of Combat-Related Posttraumatic Stress Disorder

The association of service members’ combat-related PTSD with partners’ distress is weaker when spouses/partners believe that service members experienced more traumatic events during deployment. Also, when simultaneously examining partners’ perceptions of all PTSD symptoms, perceptions of reexperiencing symptoms (the symptoms most obviously connected to traumatic events) are significantly negatively related to distress in partners. These findings are consistent with the notion that partners may be less distressed if they make external, rather than internal, attributions for service members’ symptoms. The present study explicitly tests this possibility. Civilian wives of active duty service members completed measures regarding their own marital satisfaction, their perceptions of service members’ combat exposure during deployments, their perceptions of service members’ symptoms of PTSD, and their attributions for those symptoms. External attributions were significantly positively associated with perceptions of combat exposure (r_p = .31) and reexperiencing symptoms (β = .33) and significantly negatively associated with perceptions of numbing/withdrawal symptoms (r_p = –.22). In contrast, internal attributions were significantly negatively associated with perceptions of reexperiencing symptoms (β = –.18) and significantly positively associated with perceptions of numbing/withdrawal symptoms (β = .46). Internal attributions significantly moderated the negative association of PTSD symptoms with marital satisfaction, such that the association strengthened as internal attributions increased. These findings are the first explicit support for an attributional understanding of distress in partners of combat veterans. Interventions that alter partners’ attributions may improve marital functioning.     

Young children’s acquisition of knowledge about the Earth: A longitudinal study

This longitudinal study examined the acquisition of early knowledge of astronomy to determine whether children’s knowledge at any point in time is consistent with a naive “mental model.” Children were first assessed by means of open questions and drawing tasks at 2 and 3 years of age (N = 143). The knowledge was reassessed over the course of the following 3 years. The results showed that although a few indications of naive mental models were found, in most cases young children’s knowledge was fragmented and accurate knowledge was often expressed alongside inaccurate/synthetic ideas. Furthermore, it was shown that children need to know scientific facts before they start taking the global perspective when describing the world and, when faced with ambiguous open questions, children often experience difficulties that can induce them to change the types of answers they provide.