Our abilities to perceive and interpret the emotions of others are fundamental in our social lives. Unfortunately, emotion perception is not a simple process of merely passively reading objective information from another’s face and body, as some theories of emotion have claimed in the past. Instead, emotion perception appears to be an active, constructive process shaped by context, conceptual knowledge about emotions, and social bonds. Understanding the ways in which these elements shape or bias emotion perception is important because misinterpreting emotions can lead to problems in communication, from simple misunderstandings to escalated conflict. My work examines the various contexts that influence how we see, interpret, and remember others’ emotional states. This research is designed to be highly accessible and collaborative, providing significant, hands-on opportunities for undergraduate researchers at every stage of the scientific process.

The Role of Stereotyped Emotion Category Knowledge

          My initial line of research in this area focuses on the role of categorical processing biases in how we remember ambiguous facial expressions of emotion (e.g., McMullen et al., 2025; McMullen et al., in prep). In these studies, I employed a paradigm novel to emotion research called peak shift. In animal and vision science, peak shift is an established paradigm that probes categorical processing (Lynn, 2010; Nicholson & Gray, 1971) and references a stimulus generalization that occurs from discrimination learning. In this paradigm, participants first learn to discriminate between two ambiguous facial expressions drawn from the middle of a morphed array of images of facial expressions of emotion. Participants are then shown all images from the morphed array one at a time and asked to identify the two target expressions they were previously trained to discriminate. When each target expression was labeled with different emotion category words (e.g., more angry vs. more fearful) during discrimination training, I demonstrated that ambiguous facial expressions were consistently misremembered as looking less similar to one another than they were in reality and more like the stereotypical expression associated with the given emotion category label (McMullen et al., 2025). Importantly, these memory biases were reduced or absent when the target expressions were not labeled with emotion words (e.g., Face A). Further, in the absence of emotion word labels, people’s beliefs about the nature of emotion were related to the extent to which they employed categorical processing during the perception and memory of the target expressions. Specifically, those who reported more essentialist beliefs about emotions—believing emotion categories are innate and biologically based—exhibited more categorical processing biases than those with less essentialist beliefs about emotion.

          Building on this in an article currently in preparation (McMullen et al., in prep), I explore this phenomenon further by identifying the specificity and mechanisms of the bias. In this work, I highlight the critical role of category relevance by demonstrating how categorical processing is amplified only by labels that are relevant to the dimension along which the presented stimuli vary. For instance, memory biases for ambiguous facial expressions of emotion were stronger when the expressions were labeled with emotion category words compared to when they were labeled with socially relevant but non-emotional labels, such as gender category labels (e.g., more masculine, more feminine), and memory biases for ambiguously gendered faces were more pronounced when the faces were labeled with gender category terms than emotion category terms. Memory biases were also absent for ambiguous expressions when their labels signified non-membership in a particular category (e.g., not angry, not fearful). Lastly, I demonstrated that the biasing influence of emotion labels occurs during retrieval (i.e., remembering) rather than during the initial encoding (i.e., perceiving) of the ambiguous expressions. This suggests that the presence of emotion category words does not alter the initial perception of the ambiguous expressions but instead influences memory for the facial expressions during reconstruction of the memory (McMullen et al., in prep).

The Role of Personalized Knowledge and Experience

          In my current research, I am shifting away from studying the role of normative categorical or conceptual knowledge about emotions in emotion perception to the role of more idiographic knowledge in emotion perception. That is, when communicating with those close to us, we rely on deep, personalized knowledge of their emotional idiosyncrasies (Aune et al., 1994; Fischer & Evers, 2011), and this may extend to how we perceive or interpret their emotional expressions. The existing literature on close relationships and emotion perception has largely focused on romantic, familial, or other formal relationships. In contrast, there is little work on friendships, a noteworthy relationship that people seek out and engage with daily. More importantly, the limited research on emotion perception among close friends presents inconsistent evidence concerning whether friendship familiarity provides any emotion perception advantage. My dissertation research seeks to address these inconsistencies by examining when and for whom close friendships improve accuracy in emotion perception. Specifically, this project asks whether the complex, individualized conceptual knowledge gained through close relationships facilitates more consistent, context-dependent emotion perception and when this effect occurs.

          As part of this work, I am developing a unique stimulus set comprising dynamic videos of both posed and naturalistic emotional expressions. In emotion perception research, it is common for emotion expression stimuli to be static images of individuals posing stereotypical emotion expressions (e.g., a scowl for anger or a pout for sadness). However, recent critiques of the ecological validity of this methodology have been raised, including that we tend to perceive others’ emotions as they are dynamically moving their faces and bodies, as opposed to viewing a static image of their expression. Further, posed or stereotypical expressions tend to be exaggerated and not realistic; they fail to represent the immense variability people have in their expression of emotions (Krumhuber et al., 2007; Nelson & Russell, 2013). These characteristics of traditional emotion expression stimuli may be inflating recognition accuracy by constraining variability. For my dissertation, I am generating a video stimulus set of both posed and more naturalistic emotion expressions from the same individuals. The videos for posed expressions show the individual shifting their expression from neutral to one of seven different emotion categories (i.e., anger, fear, surprise, sadness, disgust, happiness, and neutral). Although posed, these videos will involve dynamic movement of the face from which perceivers can draw inferences about the expressed emotion. The videos for naturalistic expressions show spontaneous reactions to emotionally evocative videos that were selected to evoke the same seven emotion categories noted above. These naturalistic expressions more readily capture the variability and idiosyncrasy of real-world emotion.

          Undergraduates are critically involved in the execution of this project, assisting with the collection and editing of video stimuli and the creation of the individual perceiver surveys. Of importance, this approach aligns with previous efforts mentoring an undergraduate honors thesis student through a project building a gender diverse emotion expression stimulus set (Robertson, McMullen, & Wormwood, in prep). Both of these projects involved undergraduate students in a leading position, thereby broadening methodological tools available to affective scientists interested in emotion perception.

          In addition to generating this stimulus set, I will have a separate sample of perceivers view the videos of both a close friend and a stranger. They will be asked to guess which emotion category the person in the posed videos was asked to express and they will indicate the extent to which the person in the naturalistic videos was feeling each of seven emotions. By comparing perceivers’ ratings to those of the expressors gathered during the generation of the video, I will test my central dissertation hypothesis: close friends will exhibit greater consistency (a stronger match between the expressor’s self-reported experiences and the perceiver’s ratings) for their friends’ expressions than a stranger, but only for the naturalistic expressions. This work provides crucial insight into the mechanisms of generalized emotional competence and social functioning. This allows for a deeper understanding of whether personalized knowledge gained through friendships provides a real perceptual advantage, a point that is crucial for clinical and social psychology, such that it clarifies the limits of assumed understanding in close bonds. This can inform interventions and training aimed at reducing miscommunications and conflict in both close relationships and other more formal relationships like workplace interactions.

Future Work

          One focus of my ongoing and future scholarship is to continue to include undergraduate students in all phases of research, from development to publication. As an undergraduate student at Susquehanna University, I was provided with the opportunity to work in an animal research lab early in my academic career. In this lab, we studied the mechanisms for learning and memory, specifically whether memories for acute stress are susceptible to disruption. This work resulted in two co-authored publications (Briggs & McMullen, 2020, 2024) and a passion for teaching psychology and providing similar research opportunities to undergraduate students. I aim to provide a rich, hands-on experience for students. Undergraduates currently working alongside me on my dissertation are learning core research skills, such as how to ask testable research questions, programming and running detailed paradigms, managing detailed data sets, and assisting in the complex process of creating and validating stimulus sets.

          My commitment to teaching and undergraduate research serves as the foundation for a sustainable future research trajectory. In addition to continuing to explore the dynamics of close friendships in emotion perception, I am interested in expanding to include other meaningful relationships, like teacher-student relationships and romantic couples. I am also interested in integrating my initial line of research on memory biases for emotion expressions with my current dissertation work. I plan to adapt the peak shift paradigm to use the dynamic, posed, and naturalistic expressions. This would allow me to address key questions such as whether utilizing dynamic expressions leads to more veridical memory for the ambiguous expressions or if the memory biases observed in my initial studies are default biases regardless of the stimulus type. Beyond continuing to expand my current work, I am interested in exploring the perception of pain. Pain, like ambiguous expressions, can be a high-stakes subjective experience. I am interested in learning more about the basic ability of individuals to perceive pain in naturalistic settings, as well as incorporating the framework of close others to examine whether personal conceptual knowledge may reduce one’s likelihood to misinterpret expressions of pain.

          My current and future research is ideally suited to the mission of small liberal arts institutions. I view my research as a collaborative space dedicated to undergraduate mastery of psychological research, transitioning them from passive learners to active researchers. The scope and methodology of my work, leveraging readily available technology and clear experimental design, are intentionally structured to be managed and driven by undergraduates, fostering critical thinking and preparation for advanced degrees or research-intensive careers. Moreover, the goal of this collaborative research is to provide the empirical foundation needed to develop effective antibias interventions, fostering the accurate social competence that sustains both personal and interpersonal well-being.

 

 

 

 

 

 

 

 

 

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References

Aune, K. S., Aune, R. K., & Buller, D. B. (1994). The Experience, Expression, and Perceived Appropriateness of Emotions Across Levels of Relationship Development. The Journal of Social Psychology, 134(2), 141–150. https://doi.org/10.1080/00224545.1994.9711377

Briggs, J. F., & McMullen, K. M. (2020). Forget the stress: Retrograde amnesia for the stress-induced impairment of extinction retrieval. Learning & Memory, 27(5), 173–176. https://doi.org/10.1101/lm.051078.119

Briggs, J. F., & McMullen, K. M. (2024). Retrograde amnesia for the stress-induced impairment of extinction: Time-dependent and not so forgotten. Learning & Memory, 31(1–2), a053895. https://doi.org/10.1101/lm.053895.123

Fischer, A. H., & Evers, C. (2011). The Social Costs and Benefits of Anger as a Function of Gender and Relationship Context. Sex Roles, 65(1–2), 23–34. https://doi.org/10.1007/s11199-011-9956-x

Krumhuber, E., Manstead, A. S. R., Cosker, D., Marshall, D., Rosin, P. L., & Kappas, A. (2007). Facial dynamics as indicators of trustworthiness and cooperative behavior. Emotion, 7(4), 730–735. https://doi.org/10.1037/1528-3542.7.4.730

Lynn, S. K. (2010). Decision-Making and Learning: The Peak Shift Behavioral Response. Encyclopedia of Animal Behavior, 1.

McMullen, K. M., MacVittie, A., Leffers, J. S., Betz, N., & Wormwood, J. B. (2025). Categorization processes in emotion expression recognition: The roles of language and essentialism. Emotion. https://doi.org/10.1037/emo0001483

McMullen, K. M., MacVittie, A., Leffers, J. S., Betz, N., & Wormwood, J. B. (In prep). Memory Biases in Emotion Expressions.

Nelson, N. L., & Russell, J. A. (2013). Universality Revisited. Emotion Review, 5(1), 8–15. https://doi.org/10.1177/1754073912457227Nicholson, J. N., & Gray, J. A. (1971). Behavioural Contrast and Peak Shift in Children. British Journal of Psychology, 62(3), 367–373. https://doi.org/10.1111/j.2044-8295.1971.tb02047.x

Robertson, A., McMullen, K. M., & Wormwood, J. B. (In Prep). The Gender Diverse Emotion Expression Stimulus Set (GDEESS).