Task: Analyze the tweet's emotional connotations 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 best portray the tweeter's mental state.
Tweet: It is no coincidence that Lacan recorded infants' jubilant reactions to their mirror images in the noise.
This tweet contains emotions: 
sadness