Task: Evaluate the tweet for emotional cues and classify it as either 'neutral or no emotion' or as one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that indicate the tweeter's state of mind.
Tweet: It is no coincidence that Lacan recorded infants' jubilant reactions to their mirror images in the noise.
This tweet contains emotions: 
sadness