Can we infer someone's cultural group from their laugher, even when we do not know what they are laughing at? And what kind of laughter do we find most positive? A new study shows that our laughter gives us away. The study included Dutch and Japanese producers of laughter and listeners. Listeners could detect whether a laughing person is from their own or another cultural group by only hearing a brief laughter segment. Spontaneous laughter was rated as most positive by both groups.