DO INFANTS USE EMOTIONAL CUES TO PREDICT OTHERS’ ACTIONS?
BY
KRISTA WIEGMAN
A Thesis
Submitted to the Department of Psychology, Neuroscience & Behaviour
In Partial Fulfillment of the Requirements
for the Degree Honours Bachelor of Arts
McMaster University
April, 2013
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HONOURS BACHELOR OF ARTS (2013)
MCMASTER UNIVERSITY
Hamilton, Ontario
TITLE: Do infants use emotional cues to predict others’ actions?
AUTHOR: Krista Wiegman
SUPERVISORS: Dr. M.D. Rutherford and Vivian Lee
NUMBER OF PAGES: vi, 35
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Abstract
The ability to predict the actions of others is an important aspect of social interaction. The early
origins of this ability has focused largely on attentional cues, such as eye-gaze and reaching.
However, much of human behavior is driven by emotions and their underlying motivational
states. Thus, emotions serve a very important role in making predictions of how other people will
behave. Yet, little research has been conducted on the ontogeny of the ability to use others’
emotions as a cue to intentional state, and the current literature is inconclusive. As such, we
tested 18-month-olds using a looking time paradigm, in which infants were familiarized to an
actress emoting positively (Happiness) or negatively (Fear) into one of two cups. We compared
the average looking time in test trials where the actress' actions were consistent or inconsistent
with her emotion during familiarization. We reasoned that if infants were using the emotional
cues of the actress, looking time should be longer when the actress behaves in a manner that is
inconsistent with her emotional cues. However, contrary to our prediction, we found that infants
in both negative and positive emotional conditions looked longer when the actress reached into
the unattended cup. This suggests that the infants were relying on the actress’ attention cues and
are not yet capable of making predictions based on emotional cues. However, we found that
there may be a gender difference in this ability, with females showing a tendency to respond as
predicted. We suggest the need for future research to examine possible gender differences in
more depth. We also allowed infants to interact with the objects at the commencement of the
experiment in order to determine if they accurately perceived the emotion and reacted to the cup
appropriately. As predicted, we found that infants in the fear condition were less likely to interact
with the attended cup, whereas infants in the happy condition were more likely to interact with it.
The combined findings suggest that even by 18-months-old, infants reason about others emotions
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egocentrically; they use other’s emotions to modify their own interactions with objects in the
environment, however they fail to use this information to predict the behaviours of others. We
highlight some possible confounds in our experiment and discuss a follow-up study that is
currently underway to address these issues. We also outline some possible avenues for future
research.
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Acknowledgments
I would like to thank Dr. Mel Rutherford for his guidance and for providing me with this
wonderful opportunity. I would also like to thank Vivian Lee for all of her guidance and support
throughout this project. It was truly an honour working under such a talented researcher and
dedicated mentor. I would also like to extend my gratitude to Marcus Morrisey and Kriti
Chandna for their help and support throughout this past year. I would like to send a special
thanks to the actresses who put in countless hours helping to run the study; Alena Russo, Tiffany
Ng, Melissa Campos, Natasha Da Silva, and Jennifer Wells. Not only were they an immense
asset to the project, but their personal and emotional support throughout the past year is deeply
appreciated. Thank you to all the volunteers who dedicated their time to recruiting participants
and helping to run the studies. And of course, thank you to the parents and infants who
volunteered their time to make this project possible and to help further developmental research.
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