To echo the sibling comment: > we don't even have cultural concepts or language to capture this in a meaningful way I was thinking the dynamic from these bird

To echo the sibling comment: > we don't even have cultural concepts or language to capture this in a meaningful way I was thinking the dynamic from these birds shows a more "hidden" model of relationships how I have witnessed and experienced. Obviously there is no "one way", but like the birds, the majority, that I am around, fall into this pattern. Language is such a limiting factor here. By dominate aggressive females or nurturing males, it is not meant in the females emasculating males way that the phrase could be taken in English culture. As with the birds, being the nurturing male never meant the weak male. The nurturing males simply adapted to their strengths and nested in dense forest and sang their songs in a lower pitch so it farther. It doesn't mean they were less than, they still got mates. They are very attractive to both aggressive and nurturing females, but the more aggressive females are going to go after what they want when they want more often than the more subdued females. To bring it into one of many human examples I personally have decades of witnessing, is an aunt & uncle who would be considered the "power couple" of the family. Wealth, education, status, all far outshines the rest of the extended family. But depending on when you witness them, they would be classed power couple, conservative-traditional couple, or egalitarian/50-50 type. At one point, both high powered careers, the female with the higher position (multinational financial VP type). Eventually she decides to take care of the house and he continues working raking in good money. At no point in time would anyone who knows them, ever in their right mind, call her nurturing and him dominate. If boundaries needed to be made with family, friends, brokers whoever she was on it and it was no-nonsense. You could find him tending to their garden, or chatting it up with neighbors in the mean time. There was nothing emasculating about it. And if I had to make a guess about which of the family couples that have been married 40+ years still has the sex life one could only dream of when they reach their late 60-70's - its them.