(1) Enforced celibacy
There was a custom which prohibited men to approach women during their pregnancy and breast feeding of the child. Thus, due to the long term of enforced celibacy, a man might have preferred to go for a second marriage.
(2) Limited male population
There are some societies where the number of women is more than the number of men resulting polygyny.
(3) Social prestige
In tribal community people believe that the man who have more wives, the higher his position and respect in the society. In order to prove their superiority the tribal leaders want to have more than one wile.
(4) Taste of variety
Another cause of polygyny is man’s taste for variety. Long familiarity dulls sex instinct hence the desire of change can be fulfilled only by the polygyny.
(5) Bareness of women
If the wife is incapable of producing a child or bearing only female children, the husband has to marry second time.
(6) Economic necessity
Economic utility is a possible cause for polygyny because the husband who is a farmer engage his wives in the agricultural fields and saves the wages.