<p>Perceiving others’ emotional facial and vocal expressions is nearly effortless for adults, and most discrete emotions are universally recognizable. Although the ability to accurately detect and distinguish emotions is present in adulthood, it is still unclear how this ability develops early in life. Both behavioral and neurocognitive studies suggest that in the first year of life, infants can differentiate discrete emotions; however, this is only evidenced by differential processing of emotions that belong to contrasting valence categories (positive vs. negative); it remains unclear whether infants demonstrate differential processing of emotions that belong to the same valence category (i.e., negative emotions). I considered the limitations of classic paradigms used to investigate emotion processing in infancy and the gaps left in the literature as a consequence, and conducted two experiments that explore new avenues to measure infants’ ability to differentiate negative emotions. These studies investigated how infants integrate sensory information and differentially respond to facial expressions to understand how infants distinguish between negative emotions. </p>