Something that Robert Provine has pointed out, as you can see here, and the reason why we were laughing when we heard those funny laughs at the start, and why I was laughing when I found my parents laughing, is that it's an enormously behaviorally contagious effect.
Robert Provine istaknuo je da smo se smijali onim smiješnim smjehovima s početka i zašto sam se ja smijala  vidjevši roditelje jest zbog njegove iznimne  bihevioralne zaraznosti.