Research Interests

The ability to categorize people arises early in human development. This ability is useful for navigating our complex social world but can also result in negative consequences, such as prejudice, discrimination, and stereotyping. How do such early emerging socio-cognitive abilities that initially help us navigate the social world later hinder us from creating an equitable society? My research examines how the social environment shapes these early emerging socio-cognitive abilities, and how features of the social environment have differential impact on majority versus minority members of our society. Specifically, I examine (1) how racial and linguistic diversity in neighborhood, community, and cultural contexts shape social group conception in racial majority and minority children; (2) how a person’s accent is an important social marker in addition to race; and (3) how children think about social exclusion and inequalities. I examine these processes in racially, linguistically, and culturally diverse populations and use a variety of interdisciplinary methods across psychology, neuroscience, physiology, and sociology from infancy to childhood.

  1. Social environment shapes social biases

Enduring racial inequality indicates that racial discrimination is deeply ingrained in the psychological processes that generate human social behavior. Yet these tendencies are not present at birth and likely malleable early in life. Discriminatory tendencies may arise from an asymmetrical exposure to different social group members early in life, but relatively little is known about the relations between early social experience and the complex cognitive and affective processes involved in social biases. The primary goal of my research is to investigate how social experience, in particular contact with racial and linguistic diversity, relates to the development of social bias. I utilize behavioral and electroencephalography (EEG) to investigate neural signatures of affective and cognitive processes behind how infants view people from different racial or linguistic backgrounds and whether biases in infants’ cognitive and/or affective processing are influenced by exposure to racial and linguistic diversity.

I find evidence that starting from infancy, neighborhood environments may already shape race perception (Hwang, Meyer, Debnath, Salo, Fox, & Woodward, 2021). Specifically, I found that 7- to 12-month-old White infants from more racially diverse neighborhoods exhibited greater frontal theta oscillation (an index of top-down attention) and more mu rhythm desynchronization (an index of motor system activation and action mirroring) to a person of color than White infants from less racially diverse neighborhoods. That is, White infants from racially diverse neighborhoods were more likely to pay attention to and exhibit greater action mirroring when they see a person of color than White infants from racially homogeneous neighborhoods. Is this because infants felt more positively toward people of color? No, because neighborhood racial demographics did not relate to White infants’ frontal alpha asymmetry (a measure of affective approach-withdrawal motivation) toward a person of color. These results bring into question the intuitive assumptions that affective or emotional processing (e.g., liking familiar same race people and disliking unfamiliar different race people) drive social biases early in life; rather, infants’ attentional and mirroring mechanisms may play a more crucial role in shaping infants’ initial responses to people from different racial backgrounds. I am currently replicating this finding and recruiting a larger sample of racial minority infants to better examine their neural responses. My findings indicate the potential power of neighborhood environment in shaping social bias starting in the first year of life and launch an exciting new direction in studying social biases in infancy.

To quantify infants’ and children’s daily social interactions with racially diverse individuals in addition to neighborhood level exposure to racial diversity, I utilize an infant/child-appropriate social network survey with collaborator Dr. Nicole Burke. I examine infants’ looking behaviors and naturalistic social behaviors to examine how racial diversity in the social environment influence these behaviors in response to interacting with different race individuals. I am currently collecting data using this survey tool on an online platform ( to examine whether racial diversity in infants’ social networks is related to infants’ expectations about interracial interactions. I am also conducting secondary analyses on large-scale child temperament datasets to examine whether infants’ stranger fear and children’s social behaviors towards new peers are modulated by race and racial diversity in their neighborhoods. I predict that infants and children from racially diverse social environments will be less surprised by positive interracial interactions and show less fear or negative behaviors towards a different race stranger than infants and children from racially homogeneous environments. I have received a K99/R00 award to fund this research.

I also plan to continue examining how neural mechanisms can help us understand which early emerging cognitive and affective processes contribute to the formation of social biases. I plan to conduct studies on how infants’ and children’s EEG activity map onto foundational socio-cognitive behaviors, such as imitation, helping, and empathy behaviors, when interacting with people from different racial and linguistic groups and with varying exposure to racial and linguistic diversity. By examining the fundamental blocks of social behaviors and neural correlates that predict these behaviors across infancy to childhood, I will examine how these behaviors and neural mechanisms may be precursors to more malicious social biases that take hold later in adulthood. I have recently submitted a R01 grant to fund this effort with collaborators Drs. Amanda Woodward, Nathan Fox, and Marc Colomer Canyelles.

Although exposing infants and children to more racially diverse people and environments may be helpful in combating social biases, in reality, our current U.S. society is often racially segregated. The city of St. Louis, where I completed my Ph.D., is a region starkly divided across racial and economic lines and infamous for the Delmar divide: neighborhoods south of Delmar blvd are 70% White, whereas the neighborhoods north of Delmar blvd are 98% Black. Does living in these racially homogeneous environments cause children to show more preference for their own race due to limited exposure – or do children already notice societal messages about race and show a “White is good” bias (Clark & Clark, 1947; Hirschfeld, 1993) regardless of their social environment? I found that overall 3- to 7-year-old White children from south of Delmar and Black children from north of Delmar both preferred White over Black teachers. This pro-White preference in Black children was especially striking, given that these children attended schools in which their own race was the majority in the teacher and student population. However, despite this overarching pro-White bias, classroom teacher race was related to White children’s racial preferences: having a classroom teacher of color increased White children’s likelihood of preferring Black teachers. In contrast, having a classroom teacher of color did not change Black children’s racial preferences (although Black teachers are critical for other positive outcomes, such as educational attainment and mentorship; see Gershenson, et al., 2018). This differential impact of exposure points to how societal level biases – beyond immediate, dyadic interactions – could exert a contrasting influence on Black children compared to White children (see also Tatum, 1997). Collectively, this line of research highlights the value of studying environmental impact on race perception early in life and including children from diverse backgrounds to better understand how societal contexts shape emerging social biases.

  1. Accent is another source of social bias

Research on diversity often focuses on race, but recent studies, including my own work, reveal that language and accent are also incredibly consequential group markers that even young children use to divide our social world. Language and accent can often mark one as an outsider and is the source of prejudice toward many immigrant populations. My research shows that children’s early language environment can impact how they use language and accent to make social judgments about others (DeJesus, Hwang, Dautel, & Kinzler, 2017b): monolingual White American children preferred to befriend English speakers over Korean speakers, but bilingual Korean American children were equally open to befriending English and Korean speakers. However, both groups of children preferred American-accented speakers over Korean-accented speakers. Although bilingual Korean American children had immigrant parents who spoke with a Korean accent and had extensive exposure to Korean-accented speech, they still preferred American accents over Korean accents. This work demonstrates that children’s social preferences are not based solely on familiarity and suggests that children are potentially sensitive to social meaning and status associated with accents.

To further test the idea that children use accent as a group marker with social meaning, I examined what kinds of inferences children make about foreign accents (Hwang & Markson, 2018). Do children avoid foreign-accented speakers because they think that the speakers are incompetent language users or because they assume that speakers are “not from here”? I explored this question in a large-scale museum-based study. I investigated whether 5- to 8-year-old monolingual children use proficiency in syntax, semantics, and phonology when making social judgments, such as judging whether a person is “from here” vs. “somewhere else” and whom to befriend. Children judged foreign accented speakers as less likely to be “from here” and were less likely to befriend them than native accented speakers who were not proficient in syntax or semantics. These results suggest that children are inferring foreign accented speakers as not simply linguistically incompetent but as outsiders who are not part of their social group.

Language group membership also appears to take priority over racial group membership in children’s social cognition. My research suggests that children show surprisingly similar developmental trends in the use of language and race as a group marker across different countries (DeJesus, Hwang, Dautel, & Kinzler, 2017a). Specifically, I compared White and Korean American children (who were recruited from the racially diverse city of Chicago) to South Korean children (who were recruited from Seoul, a major city in one of the most ethnically homogeneous countries in the world). Regardless of their backgrounds, children aged 5 to 6 prioritized language over race when deciding the nationality of a person. For instance, 5- to 6-year-old children from both the U.S. and South Korea judged an ethnically Korean individual who spoke English as “American.” However, with age, children showed increasing awareness of race that reflected their respective cultural contexts. By ages 9 to 10, all children increased in using race as a marker of nationality and Korean children from South Korea actually prioritized race over language (e.g., they considered a Korean individual who spoke English as “Korean”). This developmental trend suggests that children prioritize what language the person speaks over the person’s race in early childhood but later learn to use race as a group marker.

  1. Early emerging understanding of social exclusion and social inequities

How do children begin to comprehend the consequence of social categorization? To do so, children need to first identify and understand social exclusion. Identifying social exclusion in everyday interactions is a first step toward comprehending more complex societal inequities. My research indicates that while 2-year-old children struggle to notice when someone is left out from a group, 3-year-old children can reliably identify when someone is left out (Hwang, Marrus, Irvin, & Markson, 2017; Hwang & Markson, 2020). I also demonstrate that increased pupil dilation occurs when experiencing social exclusion regardless of whether the exclusion is intentional (Hwang, Suh, Balbona, Sodhi, & Markson, 2019), which suggests indiscriminate physiological arousal occurs when experiencing social exclusion. These findings demonstrate that pupillometry is a promising method to investigate nonverbal responses to social exclusion in preverbal children and clinical populations, such as children with Autism Spectrum Disorder (ASD).

To date, my research demonstrates that the racial and linguistic diversity at the community level can have a profound impact on social group conception starting in the first year of life – much earlier than previously thought. I aim to create a theoretical model that specifies how environmental factors interact with developmental periods to shape social bias development. In the short term, I will examine how the development of social biases is shaped by social networks, neighborhoods, and majority vs. minority status across infancy to childhood. In the long term, I aim to answer whether there are crucial developmental periods when social biases are most malleable, how long-lasting the impacts of early exposure to diversity are, and how internalized racism starts to emerge. The ultimate aim of this work is to find the most effective ways to address social biases and create a more inclusive society.