Only the eldest son was allowed to take a wife or wives from his own caste. The younger sons either remained celibate or else formed permanent or semipermanent liaisons with women from the somewhat lower matrilineal castes (see the article on Nayars ).
Although only the oldest son could marry, he was allowed up to three wives at a time. Girls tended to be married to households within a two-to three-days' walk from their Native illam. Postpubertal marriage was most frequent. Dowries were quite high, and getting a girl married was considered a burden to her family. Sometimes a man might take a second wife in exchange in order to save on the dowry for his daughter. After marriage a girl had no rights in her natal home, and whether she was happy or miserable she simply had to bear it. Many Nambudiri women felt that being a Nambudiri woman was the worst fate any human being could have, and they sometimes prayed that no one should ever "be born a Nambudiri woman."
The size and composition of the domestic unit has varied over time. Traditionally it included a man and his wife or wives and their children, his unmarried brothers, and any unmarried sisters that might remain. It was often a three-generation unit with power and authority always vested in the oldest living male. When laws were passed permitting younger sons to marry, households sometimes came to include the wives and children of brothers, though by then these large households had begun to partition.
Traditional inheritance was in the male line and property was kept intact through the rule of primogeniture and impartibility. This has greatly changed since the 1920s and 1930s.