Because of our big brains babies take a long time to grow. They need a lot of nurturing and looking after. They take forever to become independent (around sixty years!)
Because of this they need two parents to provide the care, love and stimulation.
It’s bloody hard work.
Hence evolution has created a mechanism to ensure babies are brought up and cared for. It is pair-bonding. We call it love.
We fall in love and stay together. It’s all to do with hormones, pheromones and chemistry.
Being in love is a biological phenomenon evolved to keep two animals together long enough to bring their children up to an age when they are relatively independent (round about the age of sixty five!)
Being in love causes changes in brain chemistry resulting in euphoria, obsession with the partner and intense sexual stimulation. This great sex results in babies.
The intensity reduces but the relationship is fostered by this chemistry. It usually lasts for about seven years – long enough for a child to become relatively self-sufficient.
We need both partners to bring up a child.
In Africa they say that it takes a whole village to bring up a baby!