So let me get this right. The parasite Toxoplasma gondii changes the behaviour of the rats it infects when they eat cat faeces by making said rats less scared of cats, which makes them more liable to be eaten by said cats, which is good for said parasite as it helps it complete its life cycle. More than weird enough. But the little bugger also affects the behaviour of the humans it infects, and may contribute to cultural diversity? Get outta here!