I'm carrying out an exploratory PCA, followed by an CFA, to test for dimensionality of a questionnaire. I am wondering about the effect of having family members in the same sample.
I have a final sample of 1060 in total. This is made up of 530 autistic men (39 of whom are parents) and 530 autistic women (39 of whom are parents), with each sample matched approximately by age. It is fairly likely that the children of these parents also completed the questionnaire and would be included in the sample, although there is no way of knowing which respondents these are.
Should I remove the parents because the common home environment may lead to specific shared interests/lack of interests, thereby contributing to common variance in the factor analysis? I thought that this would be minimal as they would only be in clusters of twos or threes or fours, and it would be a shame to eliminate all 78 participants.
I'd really appreciate any help, thank you so much!