The phenomenon you are describing is related to the psychology of humor and social dynamics. When someone tells a joke and then laughs at it themselves, it can affect how we perceive and respond to the humor. Several reasons might explain why we may not find it as funny or may not laugh along in such situations:
Lack of surprise: Laughter is often triggered by a sense of surprise or incongruity, where the punchline deviates from our expectations. When the joke-teller laughs at their own joke, it reduces the element of surprise for the listener, making it less funny.
Social cues: Laughter is contagious and is often triggered by hearing others laugh. When someone laughs at their own joke, it may feel forced or insincere, making it less likely for others to join in.
Incongruity with social norms: In many cultures, laughing at one's own jokes excessively might be seen as attention-seeking or self-centered behavior. This perception could make others less inclined to join in the laughter.
Empathy and identification: When someone else laughs at their own joke, it can create a sense of separation between the joke-teller and the listener. The listener may not feel as connected to the humor since they didn't experience the same moment of wit or creativity.
Humor appreciation differs: Different people have different senses of humor, and what one person finds hilarious might not resonate with another. When the joke-teller laughs at their own joke, it may highlight a difference in humor appreciation, making it less likely for others to laugh along.
Despite these reasons, it's important to remember that humor is subjective, and individual reactions can vary. Some people might find it endearing when someone laughs at their own joke, while others may not. In the end, the context, delivery, and the relationship between the joke-teller and the listener all play a role in determining the overall impact of a joke and whether it leads to shared laughter.