Lex Fridman has discussed various aspects of crying, its origins, and its significance in multiple episodes. Here are some insights:

  1. Emotions and Social Communication: Crying is seen as a powerful, involuntary signal that communicates an individual's need for social help and connections. Karl Deisseroth explains that crying likely evolved from respiratory control mechanisms in the brain and became a valuable social signal for indicating a true emotional state, such as fear or anxiety 1 2.

  2. Personal Reflection: Lex reflects on how crying can be a profound experience that reflects deeper emotional states. In conversation with Sarma Melngailis, they discuss how crying can be a relief even when triggered by simple, joyful events, indicating something deeper is at play emotionally 3.

    The Origin of Crying

    Karl explains how optogenetics helped to identify the origin of crying, which arose from a slightly misdirected long-range projection that was there to regulate breathing. The involuntary crying became valuable as a true signal for social beings because it landed in a great area for social communication.

    Lex Fridman Podcast

    Karl Deisseroth: Depression, Schizophrenia, and Psychiatry | Lex Fridman Podcast #274
  3. Emotions in Solitude: Emotions, including crying, aren't solely for social interactions but also for personal experiences and processing emotions. Rana el Kaliouby notes that people often express emotions, such as crying, even when they are alone 4.

  4. Technology and Emotional Responses: Lex discusses how he sometimes feels emotional responses, including crying, in the context of programming and the rapid advancement of AI, which reflects a blend of excitement and sadness over the loss of innocence and personal touch in familiar tasks 5.

These discussions underline the complexity of crying, both as a physiological response and a deep-rooted social communication tool.