Hands as sex cues: sensitivity measures, male bias measures, and implications for sex perception mechanisms

Experience-dependent reshaping of body gender perception

Protracted exposure to specific stimuli causes biased visual aftereffects at both low- and high-level dimensions of a stimulus. Recently, it has been proposed that alterations of these aftereffects could play a role in body misperceptions. However, since previous studies have mainly addressed manipulations of body size, the relative contribution of low-level retinotopic and/or high-level object-based mechanisms is yet to be understood. In three experiments, we investigated visual aftereffects for body-gender perception, testing for the tuning of visual aftereffects across different characters and orientation. We found that exposure to a distinctively female (or male) body makes androgynous bodies appear as more masculine (or feminine) and that these aftereffects were not specific for the individual characteristics of the adapting body (Exp.1). Furthermore, exposure to only upright bodies (Exp.2) biased the perception of upright, but not of inverted bodies, while exposure to both upright and inverted bodies (Exp.3) biased perception for both. Finally, participants' sensitivity to body aftereffects was lower in individuals with greater communication deficits and deeper internalization of a male gender role. Overall, our data reveals the orientation-, but not identity-tuning of body-gender aftereffects and points to the association between alterations of the malleability of body gender perception and social deficits.

Asymmetric visual representation of sex from human body shape

We efficiently infer others' states and traits from their appearance, and these inferences powerfully shape our social behaviour. One key trait is sex, which is strongly cued by the appearance of the body. What are the visual representations that link body shape to sex? Previous studies of visual sex judgment tasks find observers have a bias to report "male", particularly for ambiguous stimuli. This finding implies a representational asymmetry - that for the processes that generate a sex percept, the default output is "male", and "female" is determined by the presence of additional perceptual evidence. That is, female body shapes are positively coded by reference to a male default shape. This perspective makes a novel prediction in line with Treisman's studies of visual search asymmetries: female body targets should be more readily detected amongst male distractors than vice versa. Across 10 experiments (N = 32 each) we confirmed this prediction and ruled out alternative low-level explanations. The asymmetry was found with profile and frontal body silhouettes, frontal photographs, and schematised icons. Low-level confounds were controlled by balancing silhouette images for size and homogeneity, and by matching physical properties of photographs. The female advantage was nulled for inverted icons, but intact for inverted photographs, suggesting reliance on distinct cues to sex for different body depictions. Together, these findings demonstrate a principle of the perceptual coding that links bodily appearance with a significant social trait: the female body shape is coded as an extension of a male default. We conclude by offering a visual experience account of how these asymmetric representations arise in the first place.

Perceiving emotion and sex from the body: evidence from the Garner task for independent processes

The appearance of the body signals socially relevant states and traits, but the how these cues are perceived is not well understood. Here we examined judgments of emotion and sex from the body's appearance. Understanding how we extract these cues is important because they are both salient and socially relevant. Participants viewed body images and either reported the emotion expressed by each body while ignoring its sex, or else reported the sex while ignoring its emotion. Following Garner's logic, two types of blocks were compared. In control blocks, the task-irrelevant dimension was fixed (e.g. all male in an emotion judgment task), whereas in orthogonal blocks it varied orthogonally to the task-relevant dimension (e.g. male-female). Where two dimensions draw on shared processes, interference results in relatively slower responses during orthogonal blocks. In contrast, a finding of no Garner interference - efficient selection of the task-relevant dimension - is taken to reflect independent processes. Bayesian analyses revealed evidence of no Garner interference between sex and emotion judgments, showing that extraction of these distinct signals from the body's appearance proceeds along largely parallel processing streams. These findings are informative about the mental architecture behind our perception of socially relevant characteristics of other people.

Is Man the Measure of All Things? A Social Cognitive Account of Androcentrism

Androcentrism refers to the propensity to center society around men and men's needs, priorities, and values and to relegate women to the periphery. Androcentrism also positions men as the gender-neutral standard while marking women as gender-specific. Examples of androcentrism include the use of male terms (e.g., he), images, and research participants to represent everyone. Androcentrism has been shown to have serious consequences. For example, women's health has been adversely affected by over-generalized medical research based solely on male participants. Nonetheless, relatively little is known about androcentrism's proximate psychological causes. In the present review, we propose a social cognitive perspective arguing that both social power and categorization processes are integral to understanding androcentrism. We present and evaluate three possible pathways to androcentrism deriving from (a) men being more frequently instantiated than women, (b) masculinity being more "ideal" than femininity, and/or (c) masculinity being more common than femininity.

If there's a penis, it's most likely a man: Investigating the social construction of gender using eye tracking

In their foundational work on the social construction of gender, Kessler and McKenna (1978) investigated the relationship between gender attribution and genital attribution. We used digital reproductions of the original stimuli to replicate their findings in the current social context. To further investigate the underlying decision processes we applied eye tracking. The stimuli shown varied in the composition of gender cues: from those more commonly associated with maleness to associated with femaleness. Applying the ethnomethodological approach originally used, participants were asked to decide for each stimulus whether they saw a man or a woman and to indicate subjective confidence with the decision. In line with the original results we found that the genital attribution contributed immensely to the gender attribution. Also, male gender was ascribed more often when the penis was present than was female gender when the vulva was shown. Eye tracking revealed that overall most dwell time as a proxy for important information was dedicated to the head, chest and genital areas of all the stimuli. Total dwell time depended on whether the gender attribution was made in line with the depicted genital, if the genital was a penis. Attributing female gender when a penis was present was associated with longer total dwell time, unlike attributing male gender with a vulva shown. This is indicative of higher cognitive effort and more difficulty ignoring the penis as opposed to the vulva. We interpret this finding in context of the persistent male dominance as well as to the socio-cultural understanding of the vulva as a concealed and therefore seemingly absent organ. In summary, we were able to show that the gender attribution is still closely linked to genital attribution when having a binary forced choice task and that the penis is a special cue in this attribution process.

Converging Evidence of Ubiquitous Male Bias in Human Sex Perception

Visually judging the sex of another can be achieved easily in most social encounters. When the signals that inform such judgements are weak (e.g. outdoors at night), observers tend to expect the presence of males-an expectation that may facilitate survival-critical decisions under uncertainty. The present aim was to examine whether this male bias depends on expertise. To that end, Caucasian and Asian observers targeted female and male hand images that were either the same or different to the observers' race (i.e. long term experience was varied) while concurrently, the proportion of targets changed across presentation blocks (i.e. short term experience change). It was thus found that: (i) observers of own-race stimuli were more likely to report the presence of males and absence of females, however (ii) observers of other-race stimuli--while still tending to accept stimuli as male--were not prone to rejecting female cues. Finally, (iii) male-biased measures did not track the relative frequency of targets or lures, disputing the notion that male bias derives from prior expectation about the number of male exemplars in a set. Findings are discussed in concert with the pan-stimulus model of human sex perception.

Man, You Might Look Like a Woman-If a Child Is Next to You

Gender categorization seems prone to a pervasive bias: Persons about whom null or ambiguous gender information is available are more often considered male than female. Our study assessed whether such a male-bias is present in non-binary choice tasks and whether it can be altered by social contextual information. Participants were asked to report their perception of an adult figure's gender in three context conditions: (1) alone, (2) passively besides a child, or (3) actively helping a child (n = 10 pictures each). The response options male, female and I don't know were provided. As a result, participants attributed male gender to most figures and rarely used the I don't know option in all conditions, but were more likely to attribute female gender to the same adult figure if it was shown with a child. If such social contextual information was provided in the first rather than the second block of the experiment, subsequent female gender attributions increased for adult figures shown alone. Additionally, female gender attributions for actively helping relative to passive adults were made more often. Thus, we provide strong evidence that gender categorization can be altered by social context even if the subject of gender categorization remains identical.

A Bayesian approach to person perception

Here we propose a Bayesian approach to person perception, outlining the theoretical position and a methodological framework for testing the predictions experimentally. We use the term person perception to refer not only to the perception of others' personal attributes such as age and sex but also to the perception of social signals such as direction of gaze and emotional expression. The Bayesian approach provides a formal description of the way in which our perception combines current sensory evidence with prior expectations about the structure of the environment. Such expectations can lead to unconscious biases in our perception that are particularly evident when sensory evidence is uncertain. We illustrate the ideas with reference to our recent studies on gaze perception which show that people have a bias to perceive the gaze of others as directed towards themselves. We also describe a potential application to the study of the perception of a person's sex, in which a bias towards perceiving males is typically observed.

Gaining the upper hand: evidence of vertical asymmetry in sex-categorisation of human hands

Visual perception is characterised by asymmetries arising from the brain's preferential response to particular stimulus types at different retinal locations. Where the lower visual field (LVF) holds an advantage over the upper visual field (UVF) for many tasks (e.g., hue discrimination, contrast sensitivity, motion processing), face-perception appears best supported at above-fixation locations (Quek & Finkbeiner, 2014a). This finding is consistent with Previc's (1990) suggestion that vision in the UVF has become specialised for object recognition processes often required in "extrapersonal" space. Outside of faces, however, there have been very few investigations of vertical asymmetry effects for higher-level objects. Our aim in the present study was, thus, to determine whether the UVF advantage reported for face-perception would extend to a nonface object - human hands. Participants classified the sex of hand images presented above or below central fixation by reaching out to touch a left or right response panel. On each trial, a briefly presented spatial cue captured the participant's spatial attention to either the location where the hand was about to appear (valid cue) or the opposite location (invalid cue). We observed that cue validity only modulated the efficiency of the sex-categorisation response for targets in the LVLVF and not the UVF, just as we have reported previously for face-sex categorisation (Quek & Finkbeiner, 2014a). Taken together, the data from these studies provide some empirical support for Previc's (1990) speculation that object recognition processes may enjoy an advantage in the upper-hemifield.

Seeing the world topsy-turvy: The primary role of kinematics in biological motion inversion effects

Physical inversion of whole or partial human body representations typically has catastrophic consequences on the observer's ability to perform visual processing tasks. Explanations usually focus on the effects of inversion on the visual system's ability to exploit configural or structural relationships, but more recently have also implicated motion or kinematic cue processing. Here, we systematically tested the role of both on perceptions of sex from upright and inverted point-light walkers. Our data suggest that inversion results in systematic degradations of the processing of kinematic cues. Specifically and intriguingly, they reveal sex-based kinematic differences: Kinematics characteristic of females generally are resistant to inversion effects, while those of males drive systematic sex misperceptions. Implications of the findings are discussed.