Robin Stewart Samuel Kramer

Robin Stewart Samuel Kramer
University of Lincoln · School of Psychology

PhD

About

94
Publications
37,855
Reads
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1,413
Citations
Introduction
I am currently interested in face perception and recognition. I use experimental methods, as well as computational modelling techniques, in order to better understand how we perceive, learn, recognise, and represent faces.
Skills and Expertise

Publications

Publications (94)
Article
Full-text available
A wealth of studies have shown that humans are remarkably poor at determining whether two face images show the same person or not (face matching). Given the prevalence of photo-ID, and the fact that people employed to check photo-ID are typically unfamiliar with the person pictured, there is a need to improve unfamiliar face matching accuracy. One...
Article
Full-text available
When you describe yourself and the people you know, the words you use might be different for each person. Maybe your sister is creative, and your brother is friendly. You could even describe your dog as playful and your neighbor’s cat as nervous! The descriptions are different because each of you has a different personality—that is, you differ from...
Article
Kruger and Dunning (1999) described a metacognitive bias in which insight into performance is linked to competence: poorer performers are less aware of their mistakes than better performers. Competence-based insight has been argued to apply generally across task domains, including a recent report investigating social cognition using a variety of fa...
Article
Full-text available
When items are presented sequentially, the evaluation of the current item is biased by both the previous item’s value (perceptual bias) and the previous response given (response bias). While these biases have been identified in judgements of facial attractiveness, it is unclear as to whether they produce assimilation and/or contrast effects. Here,...
Preprint
Recently in this journal, Bilgin and Wolke (2020) published a paper which showed no association between leaving infants to ‘cry it out’ and infant-mother attachment. In our commentary (Davis & Kramer, 2021), we argued that the study was underpowered and, as such, could not be considered a conclusive demonstration that ‘cry it out’ had no adverse ef...
Article
Full-text available
Automatic facial recognition technology (AFR) is increasingly used in criminal justice systems around the world, yet to date there has not been an international survey of public attitudes toward its use. In Study 1, we ran focus groups in the UK, Australia and China (countries at different stages of adopting AFR) and in Study 2 we collected data fr...
Article
Objective: The importance of breastfeeding for both maternal and infant health is well established. However, it remains the case that only a small percentage of infants are breastfed after the first six months of life. Maternal negative breastfeeding attitudes are associated with a reduced likelihood of breastfeeding an infant, but they are a mall...
Article
Full-text available
Background Although face recognition is now well studied, few researchers have considered the nature of forgetting over longer time periods. Here, I investigated how newly learned faces were recognised over the course of one week. In addition, I considered whether self-reported face recognition ability, as well as Big Five personality dimensions, w...
Preprint
Attachment styles in individuals with autism are not well understood, and research into the topic is limited to date. Authors regularly utilise standardised measures to classify attachment in adulthood, and this is the case for research with neurotypical and autistic populations. Here, we argue that there may be fundamental problems with using such...
Article
Full-text available
Previous research has shown that exposure to within-person variability facilitates face learning. A different body of work has examined potential benefits of providing multiple images in face matching tasks. Viewers are asked to judge whether a target face matches a single face image (as when checking photo-ID) or multiple face images of the same p...
Article
Psychological concerns are frequently indexed by psychometric questionnaires but the mental representations that they seek to quantify are difficult to visualise. We used a set of questionnaires designed to measure men’s concept of their bodies including: the Drive for Muscularity Scale (DMS; McCreary & Sasse, 2000), the Perceived Sociocultural Pre...
Article
Existing models of facial first impressions indicate between two and four factors that underpin all social trait judgements. Here, we submitted several large databases of these first impression ratings to unsupervised learning algorithms with the aim of clustering together faces, rather than traits, to examine the ways in which impressions may be g...
Article
Full-text available
In their recent paper published in JCPP, Bilgin and Wolke (2020a) argue that leaving an infant to ‘cry it out’, rather than responding to the child’s cries, had no adverse effects on mother–infant attachment at 18 months. This finding opposes evidence across a wide range of scientific fields. Here, we outline several concerns with the article and a...
Article
Full-text available
Deciding whether two different face photographs or voice samples are from the same person represent fundamental challenges within applied settings. To date, most research has focussed on average performance in these tests, failing to consider individual differences and within‐person consistency in responses. Here, participants completed the same fa...
Article
Full-text available
Accurate self-assessment of body shape and size plays a key role in the prevention, diagnosis, and treatment of both obesity and eating disorders like anorexia nervosa. These chronic conditions cause significant health problems, reduced quality of life, and represent a major problem for health services worldwide. Variation in body shape depends on...
Article
When evaluating items in a sequence, the current judgment is influenced by the previous item and decision. These sequential biases take the form of assimilation (shifting toward the previous item/decision) or contrast (shifting away). Previous research investigating facial attractiveness evaluations provides mixed results while using analytical tec...
Article
Full-text available
Face familiarity produces advantages for both memory and matching. By developing an internal representation through repeated experience, viewers extract identity-specific information that aids subsequent recognition. However, researchers have recently argued that this process may also result in a familiarity disadvantage, whereby specific instances...
Article
Full-text available
Research into the effects of mindfulness meditation on behavioral outcomes has received much interest in recent years, with benefits for both short-term memory and working memory identified. However, little research has considered the potential effects of brief mindfulness meditation interventions or the nature of any benefits for visual short-term...
Article
Full-text available
Hyper-realistic face masks have been used as disguises in at least one border crossing and in numerous criminal cases. Experimental tests using these masks have shown that viewers accept them as real faces under a range of conditions. Here, we tested mask detection in a live identity verification task. Fifty-four visitors at the London Science Muse...
Article
When interacting with other humans, facial expressions provide valuable information for approach or avoid decisions. Here, we consider facial attractiveness as another important dimension upon which approach-avoidance behaviours may be based. In Experiments 1-3, we measured participants' responses to attractive and unattractive women's faces in an...
Article
Full-text available
Eyewitness descriptions provide critical information for the police and other agencies to use during investigations. While researchers have typically considered the impact of memory, little consideration has been given to the utility of facial descriptions themselves, without the additional memory demands. In Experiment 1, participants described fa...
Article
Full-text available
Background: In recent years, fraudsters have begun to use readily accessible digital manipulation techniques in order to carry out face morphing attacks. By submitting a morph image (a 50/50 average of two people's faces) for inclusion in an official document such as a passport, it might be possible that both people sufficiently resemble the morph...
Article
Investigations of face identification have typically focussed on matching faces to photographic IDs. Few researchers have considered the task of searching for a face in a crowd. In Experiment 1, we created the Chokepoint Search Test to simulate real‐time search for a target. Performance on this test was poor (39% accuracy) and showed moderate assoc...
Article
Our first impressions of others, whether accurate or unfounded, have real-world consequences in terms of how we judge and treat those people. Previous research has suggested that criminal sentencing is influenced by the perceived facial trustworthiness of defendants in murder trials. In real cases, those who appeared less trustworthy were more like...
Conference Paper
Full-text available
Recently, there has been a shift towards the use of 3D scanning technology in body size perception research. Based on limitations of previous methodologies there is a need to develop and validate female body stimuli that are high-resolution, photo-realistic and biometrically accurate, and modern technology makes this possible. The aim of this proje...
Article
A paradoxical finding from recent studies of face perception is that observers are error-prone and inconsistent when judging the identity of unfamiliar faces, but nevertheless reasonably consistent when judging traits. Our aim is to understand this difference. Using everyday ambient images of faces, we show that visual image statistics can predict...
Article
Models of social evaluation aim to capture the information people use to form first impressions of unfamiliar others. However, little is currently known about the relationship between perceived traits across gender. In Study 1, we asked viewers to provide ratings of key social dimensions (dominance, trustworthiness etc.) for multiple images of 40 u...
Article
Full-text available
We know from previous research that unfamiliar face matching (determining whether two simultaneously presented images show the same person or not) is very error‐prone. A small number of studies in laboratory settings have shown that the use of multiple images or a face average, rather than a single image, can improve face matching performance. Here...
Article
Matching two different images of an unfamiliar face is difficult, although we rely on this process every day when proving our identity. Although previous work with laboratory photosets has shown that performance is error-prone, few studies have focussed on how accurately people carry out this matching task using photographs taken from official form...
Article
A growing body of research has investigated how we associate colours and social traits. Specifically, studies have explored the links between red and perceptions of qualities like attractiveness and anger. Although less is known about other colours, the prevailing framework suggests that the specific context plays a significant role in determining...
Article
Full-text available
Researchers have long been interested in how social evaluations are made based upon first impressions of faces. It is also important to consider the level of agreement we see in such evaluations across raters and what this may tell us. Typically, high levels of inter-rater agreement for facial judgements are reported, but the measures used may be m...
Data
Within-participant reliability and estimates of shared and private taste. (DOCX)
Data
Participants’ ratings for all traits. (XLSX)
Data
Different measures that are often reported in the context of scale or rater consistency. (DOCX)
Article
Full-text available
Low‐quality images are problematic for face identification, for example, when the police identify faces from CCTV images. Here, we test whether face averages, comprising multiple poor‐quality images, can improve both human and computer recognition. We created averages from multiple pixelated or nonpixelated images and compared accuracy using these...
Article
Full-text available
Background Infants and children travel using passports that are typically valid for five years (e.g. Canada, United Kingdom, United States and Australia). These individuals may also need to be identified using images taken from videos and other sources in forensic situations including child exploitation cases. However, few researchers have examined...
Article
Full-text available
Previous research has shown that displaying the color red can increase attractiveness. As a result, women display red more often when expecting to meet more attractive men in a laboratory context. Here, we carried out a field study by analyzing 546 daters from the “First Dates” television series. Each participant was filmed in a pre-date interview...
Article
Research has systematically examined how laboratory participants and real-world practitioners decide whether two face photographs show the same person or not using frontal images. In contrast, research has not examined face matching using profile images. In Experiment 1, we ask whether matching unfamiliar faces is easier with frontal compared with...
Article
It has been known for many years that identifying familiar faces is much easier than identifying unfamiliar faces, and that this familiar face advantage persists across a range of tasks. However, attempts to understand face familiarity have mostly used a binary contrast between 'familiar' and 'unfamiliar' faces, with no attempt to incorporate the v...
Poster
Full-text available
The poster explores the effects of gender and familiarity on first impressions from faces. Main findings include a negative relationship between ratings of trustworthiness and dominance for female, but not male identities as well as more consistent ratings attributed to different images of the same familiar, compared to unfamiliar, identity.
Article
Full-text available
Photographs of people are commonly said to be 'good likenesses' or 'poor likenesses', and this is a concept that we readily understand. Despite this, there has been no systematic investigation of what makes an image a good likeness, or of which cognitive processes are involved in making such a judgement. In three experiments, we investigate likenes...
Article
Full-text available
Researchers have suggested that dogs are able to recognise human faces, but conclusive evidence has yet to be found. Experiment 1 of this study investigated whether dogs can recognise humans using visual information from the face/head region, and whether this also occurs in conditions of suboptimal visibility of the face. Dogs were presented with t...
Article
As faces become familiar, we come to rely more on their internal features for recognition and matching tasks. Here, we assess whether this same pattern is also observed for a card sorting task. Participants sorted photos showing either the full face, only the internal features, or only the external features into multiple piles, one pile per identit...
Article
Full-text available
In our everyday lives, we are required to make decisions based upon our statistical intuitions. Often, these involve the comparison of two groups, such as luxury versus family cars and their suitability. Research has shown that the mean difference affects judgements where two sets of data are compared, but the variability of the data has only a min...
Article
Full-text available
Matching unfamiliar faces is known to be difficult, and this can give an opportunity to those engaged in identity fraud. Here we examine a relatively new form of fraud, the use of photo-ID containing a graphical morph between two faces. Such a document may look sufficiently like two people to serve as ID for both. We present two experiments with hu...
Data
Individual subject scores for each of the three experiments. (XLSX)
Article
Full-text available
When judging performances in a sequence, the current score is often influenced by the preceding score. Where athletes are perceived to be similar, a judgement is assimilated towards the previous one. However, if judges focus on the differences between the two athletes, this will result in a contrasting influence on their scores. Here, I investigate...
Data
Judges' scores for all synchronised diving events at the 2012 and 2016 Olympic Games
Article
We describe InterFace, a software package for research in face recognition. The package supports image warping, reshaping, averaging of multiple face images, and morphing between faces. It also supports principal components analysis (PCA) of face images, along with tools for exploring the “face space” produced by PCA. The package uses a simple grap...
Article
We describe InterFace, a software package for research in face recognition. The package supports image warping, reshaping, averaging of multiple face images, and morphing between faces. It also supports principal components analysis (PCA) of face images, along with tools for exploring the “face space” produced by PCA. The package uses a simple grap...
Article
Facial width-to-height ratio (FWHR), defined as the width of the face divided by the upper facial height, is a cue to behaviour. Explanations for this link often involve the idea that FWHR is sexually dimorphic, resulting from intersexual selection pressures. However, few studies have considered sexual dimorphism in skulls since the original paper...
Article
We learn new faces throughout life, for example in everyday settings like watching TV. Recent research has shown that image variability is key to this ability: if we learn a new face over highly variable images, we are better able to recognize that person in novel pictures. Here we asked people to watch TV shows they had not seen before, and then t...
Article
Full-text available
Forms of body decoration exist in all human cultures. However, in Western societies, women are more likely to engage in appearance modification, especially through the use of facial cosmetics. How effective are cosmetics at altering attractiveness? Previous research has hinted that the effect is not large, especially when compared to the variation...
Data
Data from Study 1. Each participant rated all 33 YouTube models, but each model appeared in a randomly selected cosmetics condition. All conditions are stated in the data. We averaged across participants for each image, building a score for each identity under both cosmetics conditions. (XLS)
Data
Data from Study 2. Each participant rated all 45 supermodels, but each model appeared in a randomly selected cosmetics condition. All conditions are stated in the data. We averaged across participants for each image, building a score for each identity under both cosmetics conditions. (XLS)
Data
Data from the quantity raters in both studies. Sheet 1 contains the quantity data from Study 1, and Sheet 2 contains the quantity data for Study 2. Participants compared each model without and with cosmetics, indicating how much cosmetics the faces were wearing. (XLS)
Article
Viewers are highly accurate at recognizing sex and race from faces-though it remains unclear how this is achieved. Recognition of familiar faces is also highly accurate across a very large range of viewing conditions, despite the difficulty of the problem. Here we show that computation of sex and race can emerge incidentally from a system designed...
Article
Full-text available
As a mild-mannered reporter, Clark Kent is able to blend into human society without drawing much attention to himself. Although he utilises several methods of disguise (clothing, posture, hair style), perhaps his most famous is a simple pair of glasses (see Figure 1). We know that wearing glasses can make you look more educated and intelligent (e.g...
Article
Full-text available
Could a simple pair of glasses really fool us into thinking Superman and Clark Kent are two different people? Here, we investigated the perception of identity from face images with a task that relies on visual comparison rather than memory. Participants were presented with two images simultaneously and were asked whether the images depicted the sam...
Poster
Several studies have focused on how dogs use visual information about human faces, but their ability to recognize the faces of familiar people is not yet understood. We tested 30 dogs on their ability to recognize their owners by using face information alone. In a series of two-choice tasks, dogs had to choose between their owner and a stranger, wh...
Article
Full-text available
Although several studies in recent years have provided evidence of a relationship between month of birth and height during childhood, the association remains less clear for adult (final) height. Here, I investigated this relationship using a large international sample of adult actors. Analyses considered both the sample as a whole, as well as subsa...
Article
Full-text available
Research has demonstrated that wearing red can have significant effects on perceptions of the wearer. However, these findings are based on impressions formed while viewing static images. Here, I focus on perceptions of political leaders and show participants short videos in order to investigate color effects in stimuli with increased ecological val...
Article
Full-text available
In recent years, researchers have investigated the relationship between facial width-to-height ratio (FWHR) and a variety of threat and dominance behaviours. The majority of methods involved measuring FWHR from 2D photographs of faces. However, individuals can vary dramatically in their appearance across images, which poses an obvious problem for r...
Data
Raw data Raw data for the three studies.
Article
The vast majority of women in modern societies use facial cosmetics, which modify facial cues to attractiveness. However, the size of this increase remains unclear-how much more attractive are individuals after an application of cosmetics? Here, we utilised a 'new statistics' approach, calculating the effect size of cosmetics on attractiveness usin...
Article
Full-text available
Research on ensemble encoding has found that viewers extract summary information from sets of similar items. When shown a set of four faces of different people, viewers merge identity information from the exemplars into a representation of the set average. Here, we presented sets containing unconstrained images of the same identity. In response to...
Article
Full-text available
Research in face recognition has tended to focus on discriminating between individuals, or "telling people apart." It has recently become clear that it is also necessary to understand how images of the same person can vary, or "telling people together." Learning a new face, and tracking its representation as it changes from unfamiliar to familiar,...
Article
Full-text available
Our recognition of familiar faces is excellent, and generalises across viewing conditions. However, unfamiliar face recognition is much poorer. For this reason, automatic face recognition systems might benefit from incorporating the advantages of familiarity. Here we put this to the test using the face verification system available on a popular sma...
Article
Full-text available
Evidence that facial width-to-height ratio (FWHR) is a sexually dimorphic morphological measure is mixed. Research has also linked FWHR with aggression and other behavioral tendencies, at least in men. Again, other research has found no such relationship. Here, I tested for both possible relationships using a sample of 2,075 male and 1,406 female a...
Article
Full-text available
Abstract Women use cosmetics to enhance their attractiveness. How successful they are in doing so remains unknown - how do men and women respond to cosmetics use in terms of attractiveness? There are a variety of miscalibrations where attractiveness is concerned - often, what one sex thinks the opposite sex finds attractive is incorrect. Here, we i...
Article
Baron-Cohen’s extreme male brain theory proposes that autism results from elevated prenatal testosterone levels. In the present study, we assessed possible correlated effects of androgen exposure on adult morphology and, in particular, the development of facial features associated with masculinity. We created composite images capturing statistical...
Article
Full-text available
In perceptual decision-making, a person's response on a given trial is influenced by their response on the immediately preceding trial. This sequential effect was initially demonstrated in psychophysical tasks, but has now been found in more complex, real-world judgements. The similarity of the current and previous stimuli determines the nature of...
Article
Depression is a common mental health disorder, with 12% of the UK population diagnosed at any one time. We assessed whether there are cues to depressive symptoms within the static, non-expressive face, and if other socially-relevant impressions might be made by these cues. Composite "average" face images were created from students scoring high and...
Article
Full-text available
Research suggests that implicit strategies adopted during learning help prevent breakdown of automatic processes and subsequent performance decrements associated with the presence of pressure. According to the Constrained Action Hypothesis, automaticity of movement is promoted when adopting an external focus of attention. The purpose of the current...
Article
Full-text available
Facial width-to-height ratio has received a great deal of attention in recent research. Evidence from human skulls suggests that males have a larger relative facial width than females, and that this sexual dimorphism is an honest signal of masculinity, aggression, and related traits. However, evidence that this measure is sexually dimorphic in face...