For the movie Pink to reach its conclusion, the filmmakers had to scratch out a series of discomfiting truths on a slate made of reassuring fictions.

I don’t mean this as a criticism. There is much to celebrate in this powerful story that left no misogynist bias in the shadows. The obvious fictions – a gifted lawyer working gratis, an unbiased judge, a fast-track court, the influential uncle not resorting to vengeful belligerence – were optimisms necessary for the narrative. How many cases can rely on even one of the above?

But it was in the unflinching, non-judgemental, fiercely united sisterhood of the three women that I wavered.

We have all been inside flats like the one in Pink. Usually, you meet women who believed other women were their guaranteed co-conspirators, one hand outstretched to hold on to each other, the other feeling for cracks in the glass ceiling. But we have been to other flats, bristling with rivalry, accusations of stolen ideas, lipsticks or boyfriends, momentary alliances forged only to isolate, police or ridicule one of the group.

Was Pink’s sisterhood a truth, or was it fiction? What makes a solid sisterhood and what breaks it down?

Sisterhood

In my experience, women raised in equitable households by able, forthright mothers, aunts, grandmothers tend to be relaxed around other women, instinctively supportive and easy to get on with. On the flip side, there is the familiar unease with encountering those raised as hand maidens of the patriarchy – they tut-tut at other women’s modesty, ideas about gender equitability or even use of the word "feminist".

Among the former group of women, the hierarchy, if any, is subtle, convivial, organic. In the latter, there is the need to enforce a pecking order generating rivalry.

Rivalry is no good for women. We must rely on each other through the long arc of our lives. We must form tight, interconnected networks, share information, advice, gossip, filthy jokes, diet tips, ludicrous middle-aged crushes, facts and observations about our constantly changing physiologies. We learn from watching our elders that these circles will carry us into our later years.

When we heard about the amplification process used by women in the White House, repeating loudly and reinforcing the authorship of ideas put forth by other women to make sure they were not drowned out as they break into the male-dominated Oval Office, we nodded. We have all had moments like these. Buoyed up by the sisterhood.

We are not meant to distrust each other. I’m no biologist but this seems to be in resonance with the natural order of things. In the wild, us fecund fe-mammals just sit around looking drab, yawning slightly, watching the boys joust antlers or rustle manes or thump chests as we wait to be impregnated by some alpha male. Then we just get on with raising the kids and bringing home the bacon. Earth’s largest mammals – whales and elephants – rely on elderly, powerful matriarchs to support the young mothers, tame feisty teens and work for the good of the herd or the pod.

Do as the bonobos

If you look at our closest relatives, bonobos and chimps, (over 96% genetically identical to humans) you realise it could have gone either way. Chimps are patriarchal – there is warfare, aggression and sexual coercion of females. In female-dominated bonobo society, there is none of that.

Take your pick of comparative research between the two sets of primates, but this decade old Scientific American piece reveals delightful resonance between bonobos and more sophisticated humans. For example, there is their sensitive temperament: in a bombing during World War II in Germany, all the bonobos in a zoo died of fright at the noise (the chimpanzees were fine). Or the fact that food causes sexual arousal in them – literally a foodgasm.

But it is the sisterhood that stands out: bonobo female coalitions go beyond blood and involve cooperation that includes ganging up together against larger males to protect other females from rape or ensure fair distribution of resources.

A strong female network, a matriarchy or sisterhood, is not about female-rule. It is a much more egalitarian system that benefits everyone, not least the men. Bonobo males stay with their mothers into their adulthood and do not have to fight each other to find a mate. Their matriarchs do that for them, peaceably.

Men, you benefit too

In old human matriarchies like the Mosuo, traditional marital roles do not exist, resulting in lower fertility rates and greater financial independence. Again, the men of the Mosuo have less responsibility, more sexual partners and can continue to live with their mothers. Indian boys, tell me that doesn’t sound brilliant?

A sisterhood is not just good for sisters, but for society. And yet, the patriarchy has set us against each other. Recommendations and directives to be modestly attired or behaved come from the fear of sexual attack (by an outsider male) and/or a sense of proprietorship or honour of an insider male.

The unrealistic biological competition we feel even past our natural prime, age being seen as losing our relevance instead of gaining matriarchal status is linked to our loss of fertility, valuable to men. Women with multiple sexual partners are judged more harshly than men with as many notches on the bedpost – again issues of male proprietorship and the authenticity of their paternity. We could go on all day.

Pink reminds you that usually, predatory and misogynistic brotherhoods, like those of the men against whom the women go to court, operate fluidly and instinctively. That is a truth we face every day. The sisterhood in the film is not a fiction, but an ideal. The girls are rock solid. Even when they momentarily disagree, there is a moving, powerful peacemaking that comes after. We are familiar with this too.

For me, what was most interesting though, was something several internet-patriarchs missed completely with their "it took a man to save them" memes. Women raised in the sisterhoods know that the matriarchy breeds, bolsters and relies on powerful men too. We know these men from our everyday lives – fathers, husbands, brothers and sons. Equals, they rely on us as we rely on them. And wrought of the sisterhood, they are mighty.