Mammals are social beings. Reptiles spawn, bury their eggs, and crawl away; mammals give birth, and mother their offspring. This isn’t a quality unique to mammals – many birds do a fine job of raising their egg-hatched young – but it is completely pervasive among the mammals. The mother-child bond sits as the center of all social relationships, the foundation for all future behavior.
Some mammals – lions, for example – share the child-raising burden. A pride of lions generally includes a creche wherein the females collaboratively and collectively preserve the welfare of all of the lion cubs. This pooling of labor frees the mother for the hunt: a lion with a new-born cub and without a creche faces the unenviable choice between starvation and leaving her cubs undefended among all of the dangers of the veld.
Other mammals, such as wolves, use highly practiced social skills to function as a single and highly effective unit. Wolves were once the top predators within many ecosystems, their focused sociability making them fierce, relentless, and very dangerous. This ‘pack behavior’ – which we harnessed as a tool when we domesticated wolves as dogs, thirty thousand years ago – emerges from a deep social awareness: wolves are always conscious of their peers.
Bats live in crowded colonies that can number in the millions. Elephants have “families” that live together throughout their decades-long lives. Dolphins frolic in “pods”, using play both to teach and to reinforce social bonds. The bison of the American Great Plains once gathered in numbers to great to be counted, making the annual migration as a single, vast body. The wildebeest of Africa and reindeer of the Arctic still do so today.
There is strength in numbers, and safety.
A few insects – most notably, ants and bees – exhibit highly social behavior. But rather than a quality of their behavior, their social nature has become the whole of the thing. Bees exist to serve the hive, ants to provide for the nest. Everything characteristic of the social insects, from metabolism to reproduction to communication, subordinates itself the social order. This social organization has made both species impressively resilient; ridding your house of an ant infestation is no easy task, nor can you simply scare away a hive of bees. A more holistic approach must be taken, considering all the ants, and all the bees. Move the hive carefully and the bees won’t mind — much. Upset those bees, and you’ll find yourself the target of a distributed yet coordinated, painful and possibly life-threatening attack. Social animals – whether insects or mammals – have a peculiar ferocity that their non-social cousins lack.
Our particular branch of the mammal tree – the primates, and within them, the smaller and more familiar group of hominids – has social qualities utterly familiar to all of us. The family forms the basic unit, and a group of families form a troupe (or tribe). The specific social dynamics of these families and tribes differ from species to species: chimpanzees are all about power and dominance; bonobos use affection and sex to maintain their relationships; gorillas sit somewhere between the two. We humans get the full menu, using power and love in equal measure as we make our way in the social world. A good parent tempers the use of power with a larger dose of affection. Both are indispensable, both parts of the behavioral ‘kit’ that came down from our ancestors.
Looking back down tree of life to the last common ancestor of the hominids, long before Homo Sapiens, or the proto-human Australopithecus, before we evolved away from the chimpanzees, (five million years ago), or the the gorillas (ten million years ago), we find a creature known as Pierolapithecus, a true ‘missing link’ connecting us to our nearest cousins. We know very little about the species – just a few bone fragments found in Spain. Smaller than us, certainly, and not yet walking upright – that comes along much later. If you squint and imagine some sort of mash-up of the characteristics of humans, chimpanzees and gorillas, you might be able to get a glimmer of what Pierolapithecus looked like.
We can say with certainty that Pierolapithecus was a profoundly social species, because all of the species descended from Pierolapithecus – including humans – live in communities rich with social signalling. Pierolapithecus lived in family units, just as gorillas, chimpanzees, bonobos and humans do. Pierolapithecus explored the same boundaries between power and affection which frame our own family lives.
While Pierolapithecus could not speak, if transported back across the ages to observe their behavior, we would understand it – because that behavior has been retained within us. Whether human or Pierolapithecus, we don’t do well on our own. Alone, we make an easy meal for a lion or wolf. A troupe, on the other hand, can mount a common defense, keeping watch, alerting others, protecting the women and children. Pierolapithecus’ social skills helped them survive in a hostile environment, filled with big and toothy predators. The troupes with the best social skills had the best chance to survive long enough to raise children to adulthood, children who learned and practiced the same social skills.
In this way, natural selection pressures have consistently honed our social nature. Long before we were human, we were social. From the moment we first expressed any social capability, those skills were put to the test, refined, applied, tested again, refined again, and reapplied endlessly, a sort of Groundhog Day of repetition which leads inevitably to gradual improvement – or extinction.
Since we’re still here, we can rest assured we learned our lessons well. The line of mammals, perhaps 200 millions years long, provided ample opportunity for trial-and-error, extinction and success. When we recognize familiar social behavior in a meerkat, we are reflecting upon that shared evolutionary process. Our social nature, beaten into us by time and testing, has fashioned all mammals into creatures capable of succeeding through cooperative effort.