To put this in my perspective.
I have three cats at home. They are silent, hardly ever meow but will occasionally purr if you stroke them in the right spot. They will also occasionally rub on you but not very often.
The two cats we have in work however are very vocal (and cute) but are not shy of vocalising themselves for attention amoungst other things (headbutting, rubbing on you etc.)
Is this just a different type of personality? Have the work cats been brought up with less attention and thus have learned that vocalising themselves is more likely to get a response?
Two of mine are siamese whereas the other is a siamese x feral. The work ones I'm unsure of but they are both sisters.