english: 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.
non_english: To, čo Robert Provine zdôraznil a môžete to tu vidieť, a dôvod, prečo sme sa smiali, keď sme počuli tie  ukážky smiechu na začiatku, a preto som sa ja smiala, keď som zbadala smiať sa rodičov, je to, že je to správanie s ohromne nákazlivým účinkom.