[R] highly biased PCA data?

[Dan Bolser]

Hello, supposing that I have two or three clear categories for my data,
lets say pet preferece across fish, cat, dog. Lets say most people rate
their preference as being mostly one of the categories.

I want to do pca on the data to see three 'groups' of people, one group
for fish, one for cat and one for dog. I would like to see the odd person
who likes both or all three in the (appropriate) middle of the other main
groups.

Will my data be affected by the fact that I have interviewed 1000 dog
owners, 100 cat owners and 10 fish owners? (assuming that each scale of
preference has an equal range). 

Cheers,
dan.