Researchers at the University of Sussex have discovered that cats use a "soliciting purr" to overpower their owners and garner attention and food." [source]
Quite silly to view cat’s ‘purrs’ as being used to 'manipulate' humans. That’s like saying that human have been manipulating cats long enough to allow cats to learn the association between their purring and bringing out the kindness in humanity. Or, putting it another way, humans sending out a clear signal to cats that they are going to be ignored till they purr.
Perhaps the masculine researchers in the team are simply projecting their own helplessness in the face of the ‘purrs’ of the feminine to get what they want, or it’s a subtle admission by the feminine in the team of the recognised value of the purr whilst being a jibe at the stupidity of the masculine.