In the 1950s, Jane Goodall observed a split in what had been a stable community of Kasekela chimpanzees living in Gombe Tanzania, with the result that members of the small breakaway group were killed off one by one by members of the original group.

Recently, the Journal Science highlighted a similar breakup involving nearly 200 chimpanzees living in Uganda’s Kibale National Park. For several decades the overall group was divided into western, central and eastern groups, but the three groups coexisted harmoniously with no signs of violence.

However, 12 years ago following the death of several members, apparently from a respiratory disease, violence broke out between the western and central groups and has remained so since.

The reasons for the breakup aren’t known, but some scientists involved in the study suggest those deaths might have involved chimps who straddled the social divide between the two groups or perhaps the ascent of new leadership hostile to the other group.

Chimpanzee groups are male dominated and well-known to be hostile to outsiders. The opposite is true of bonobo communities, who, though closely related to chimpanzees, are run by females and solve most social friction by sex between whoever seems to be upset at the time.

Violence does happen in bonobo communities but unlike chimpanzees, bonobos don’t gang up on one another and no instances of killing have been observed.

Other social species sometimes exhibit similar behavior with separate groups sometimes merging or as in case of chimpanzees, splitting with no peaceful merger in sight.

Human society is like chimpanzee society — tribalistic and prone to violence. A list of conflicts from world wars to endless regional conflicts and violence within our own country makes the point.

Frans De Waal, a well-known student of chimpanzees and other social animals once wrote a book titled, “Chimpanzee Politics,” which became a best seller because of its timing — the period when Newt Gingrich, then the Republican head of the U.S. House of Representatives and Bill Clinton, the former U.S. president, were battling it out.

The analogy was apt and recognized at the time, at least by Gingrich.

There’s another matter here to deal with: sex, and its role in tough situations.

Not so long ago, I helped run a multiple sclerosis (MS) clinic in Thunder Bay. MS is twice as common in women and tends to begin sometime between the late teens and 30s and, for some, MS progresses in a series of relapses and remissions producing cumulative deficits and disability.

Fortunately, there are several reasonably effective medications now but no cure. For some, the cumulative disabilities are very challenging to live with and, for couples, add to the strain of living together to the point where the supporting partner sometimes splits.

In my experience and that of other neurologists, males are more likely to leave a female partner affected with MS than the other way round.

Fortunately, later in life, most partners stay together, whatever the problem, although because women tend to be younger than their male partners, women tend to bear the burden of caring for sick husbands more than the other way round.

Sometimes, the extraordinary happens. One of my MS patients became severely disabled to the point of being bedridden most of the time and unable to look after her toilet or feed herself. Her husband had long since disappeared and she was looked after by her son and daughter.

Between them and some visiting help, they provided incredibly good care: she suffered from none of the pressure sores, infections or other complications of patients at that stage in the disease.

Finally, unable to swallow and breath properly, she died. Compounding the tragedy, the daughter later developed MS within a few years of her mother’s death.

Another striking difference between the sexes is the care of patients with dementia, or to be more precise, which sex writes with the most insight, empathy and practical advice about patients with dementia.

If The New York Times is any guide, women are more likely to write about dementia with insight and empathy, by far. The medical aspects of dementia diagnosis and management are similar with both sexes.

Whether the world wound be better off with more women in charge is unknown but worth a try. After all, men have been in charge for most of recorded history and some would say: look at the mess.

But male dominance may not have been the default setting in paleolithic times or even among many hunter-gatherer groups where leadership is often more shared and communal. Of course there are the unavoidables: so far, pregnancy is a female affair, but who knows, with the pace of science these days.

To return to those sometimes quarrelsome chimpanzees, evidence suggests that male chimps mellow in middle age when they are far more likely to have long standing friendships with other males and females — behavior not common when they’re young.

Frans de Waal once wrote a book about Mama, a grandmother in a well-studied troop, who despite her frailty and small size, was greatly respected by young and old alike and even alpha males. She was the peace maker in the troop, often breaking up squabbles usually started by young males.

Sound familiar?

Dr. William Brown is a professor of neurology at McMaster University and co-founder of the InfoHealth series at the Niagara-on-the-Lake Public Library.