I am not an expert in this field and wonder if the _cause_ of the testosterone drop necessarily has to affect the outcome of bonding/nurturing behaviour? For ex

I am not an expert in this field and wonder if the _cause_ of the testosterone drop necessarily has to affect the outcome of bonding/nurturing behaviour? For example, maybe all or part of the testosterone drop _is_ due to the degraded sleep quality. If that drop then still results in them being more motivated to bond with their child and less motivated to find other partners, the effect seems to be the same - the man is then still better primed for parenthood.