In every circumstance, when my son should feel sadness, he laughs. I used to chastise them for this. One day, I finally realized that his brain had wired the connection from sadness to laughter instead of to tears. He was having the correct internal reaction, but expressing an inappropriate external one, at least from neurotypical perspective. Now, I am not bothered when he laughs. In fact, I think it may be more of a blessing. Sometimes I wish I could laugh instead of cry when I’m sad.