Our Health Inheritance

Would any of these findings surprise you?

• The social relationships of the children often reflect those of the parents, more strongly the mother.
• Even after the child leaves home, those connections exist, although somewhat weakened
• The children of the “upper crust” have stronger social connections to those parental networks.
• This also holds for children more tightly bonded with mom.
• That the more "upper crust" the inheritance, the more likely the child and their parents are to be successful.

Given all the controversy around legacy admissions to college and wealthy parents being caught up in college admissions scandals, I am inclined to believe these things are true. College education, among many other metrics of social position, like one's home address and income, seems to be bound to the network of friends and kin you inherit. There is mobility between the castes (a more generic way to discuss class), but can there be any doubt that the social network you are born into often gives you a leg up?

Perhaps I should have mentioned the following at the outset. The observations about how your inherited social network can strongly predict your network and position in life are based on a 27-year study – of hyenas. Yep, many of the ways humans socialize and network are equally reflected in the behavior of other social animals, in this case, hyenas.

The study was based on 27 years of field observations of hyena clans that ranged in size from a few to more than a hundred based upon what was available to eat. Hyenas live for roughly 26 years, so the researchers saw several generations. They “can discriminate both maternal and paternal kin from unrelated hyenas, and prefer to socialize with their kin. Clanmates compete for access to killed prey, but high-ranking individuals maintain the priority of access to food.” Substitute any of our measures of survival which include income and health, for the word food, and I think we describe many of our social hierarchies. 

The researchers constructed the hyena’s social network by quantifying the frequency that specific hyenas were found together or separate. It is not an unreasonable measure; after all, you spend more time with your friends than strangers. There are other similarities. The male offspring’s relationship with Mom diminishes over time, the female, not so much. Many human mothers and fathers will attest that their daughters tend to remain emotionally and physically closer than their sons. (My mother would be one of those in agreement, as soon as I could, I moved across the country)

Of all those characteristics of a hyena’s social network, one stands out that we might ponder for healthcare. The stronger the inheritance of a social network among high-ranking members, the greater the survival of both the offspring and the mom. (I guess as with humans, fathers place third or more distally and die sooner than women) The researchers found that compared with high-ranking social networks, inheriting no social network reduced the median lifespan by about 8.4 years or roughly a third of the hyena’s average life. 

From my point of view, this speaks to what has been called the social determinants of health – the income, geography, habits, and culture of the local world in which you were born. It seems for the hyenas and humans that a great deal of what we “become” is reflected in our birth and early life circumstances. While a similar pattern between the social structure of hyenas and humans suggests a “natural” origin, it does not make it acceptable; we hold ourselves out to be better than the animals. 

If we are to lift everyone, we might well begin by finding ways to make the gifts of a high-ranking social network available to all. Whether we fully believe that income and upbringing control our destiny or not, we need to recognize that the social network we inherit can confer privilege or hindrance. 

Sources: 

Rank-dependent social inheritance determines social network structure in spotted hyenas Science Research Reports DOI: 10.1126/science.abc1966