Nambudiri Brahmin families practised a more strict version of primogeniture than Brahmin communities elsewhere in India. Under this custom, only the eldest son could marry a Nambudiri woman and thus produce an heir to the family property. Younger sons were restricted to sambandam relationships with non-Brahmin women, whom the Nambudiris considered to be concubines and whose offspring could not inherit. This tradition limited the extent of marriage within their own caste and led to the practice of hypergamy with the Nair community. Kathleen Gough notes that: