"Creatures are out there that can control brains." [pdf]
The women "spent more money on clothes and were consistently rated as more attractive", but were "less trustworthy and had more relationships with men". The men become "less well groomed undesirable loners who were more willing to fight". All "are at greater risk of being involved in car accidents". Why? Something has its tentacles in their brains.
They probably got it from that cuddly old species, the domestic cat
, which the parasite infects by making infected rats "almost taunt" the cats into eating them
Parasites in the brain alter their host's behavior.
It's not just video game fiction
. Various multi-host parasites make their living by making their hosts less ambulatory and less willing to explore,
by castrating them and making them less cautious of predators
, or by forcing their hosts to stay out all night
so as to be eaten in the morning
. These parasites offer yet another example of how stupidly clever evolution can be, and raise questions about how free "free will" really is.