A basic form of the metaphor can be stated as Causation Is Progeneration (making something happen is giving birth to it). The inference patterns of this metaphor account the folk wisdom and common sense purporting to explain kinship -- how things, qualities, ideas and behavior come about from one another. "The inner city breeds crime," "Oppression spawns violence, freedom gives rise to ingenuity."

Note that such usage implies personification of the Agent of causation or, if not that, then animation where an inanimate thing or idea takes on plant or animal life patterns. Time duration and individuation are also required to make the metaphor work. The complex, diffuse, difficult to understand workings of biological reproduction are reduced to simpler notions that out of one thing comes another.