From a BBC article:
When a Ghanaian dies, the body belongs to the family - that is the legal position.
The definition of family, in this case, does not include a spouse or children.
What could be an efficient reason behind this social norm, at least historically? The extended family is very important, it is at the center of community in Ghana. If the family where one is born (which does not include spouse or children, to use the definition in the BBC article) makes the decision about the burial (when and where), the spouse and children will try to stay in good terms with the family during their lives, so that their opinion (spouse and children's) regarding the corpse is not rejected outright when death comes. If this interpretation is true, this social norm is a mechanism to keep families well connected. Well connected families can provide help in case that one of the members of the family is in need. In this regard, the social norm of the property of the corps might contribute to strengthening family links that perform as social insurance. [Of course this interpretation might be totally of target!]