The Animal We
Still Are

Instinct, Reflex and Predisposition

Before going any further, it is worth pausing over a word we use far too easily: instinct. In everyday language, we call almost any behaviour that seems to arise without reflection instinctive. In biology and ethology, the issue is considerably more complicated. A reflex, an automatic response, an emotion, an inherited predisposition and a learned behaviour are not the same thing, even though from the outside they may look similar.

Pulling your hand away from a burning surface is a relatively simple example. Part of the response can be organised through spinal-cord circuits before the conscious experience of pain has fully formed. Protecting a child, defending a territory or cooperating with a group, by contrast, are enormously more complex behaviours. Biological predispositions, hormonal and neural systems, experience, learning and social context all play a role. In our species, we must also add a culture capable of profoundly altering how all those elements are expressed.

So when we speak here of human instincts, we should not imagine rigid instructions written into our genes. A gene does not contain the order “protect your child”, “defend your home” or “support your team”. Genes participate in building and regulating organisms whose nervous systems make certain tendencies and responses possible, and those tendencies then develop within an environment. The relationship between genes and behaviour is far more complex than a chain of commands.

Evolution does not require intention either. A DNA molecule does not want to perpetuate itself. But if certain variants help produce organisms that leave more copies of those variants in subsequent generations, their frequency can increase. After millions of years, the result can appear strikingly intentional even though there is no intention behind it.

My body did not need to understand natural selection in order to try to protect my son.

The Offspring Before Oneself

Parental protection is one of the best places to observe this logic because it forces us to abandon an overly simple view of evolution: the idea that every organism should always try to save itself first.

In many species, exactly the opposite occurs. Birds attack animals far larger than themselves when they approach the nest; mammals place themselves between a predator and their young; parents devote enormous amounts of energy to feeding offspring that cannot yet give anything back. In some species, reproducing and caring for offspring even causes a drastic reduction in the parent's own chances of survival.

This stops seeming paradoxical once we change the scale. Natural selection does not reward longevity for its own sake. A trait that allows an organism to live a long time but leaves no descendants disappears with the individual that carries it. Another trait that involves taking certain risks but sufficiently increases the survival of descendants who share part of that inheritance can spread.

In the 1960s, William D. Hamilton formalised a fundamental part of this idea through the theory of kin selection and the concept of inclusive fitness. Helping another individual can have different evolutionary consequences depending on relatedness and on the costs and benefits of the behaviour. A father does not unconsciously solve an equation before saving his child; the equation belongs to the model we use to explain why organisms capable of reacting in that way could have evolved.

And kinship does not fully explain human beings.

We Have Won

A stadium lets us observe this in an almost experimental form. Thousands of people gather to watch a small group of individuals try to put a ball into a goal more times than another group. From a purely material point of view, the result may change absolutely nothing in the spectator’s life. Yet the heart speeds up, tension appears, people shout, strangers embrace one another, and a victory can produce euphoria that lasts for hours.

And we use a particularly revealing expression: “we have won”.

I have not run. I have not touched the ball. I have not trained with the team and I probably do not personally know any of the players. Yet I do not say “they won”. I say “we won”. The group has incorporated its success into my own identity.

That does not turn football into a simple animal behaviour. It is an extraordinarily sophisticated cultural product, with rules, institutions, contracts, markets, traditions and an enormous symbolic weight. But it uses a much older capacity: our ability to identify with a group and experience part of what happens to it as though it were happening to us as well.

That is why it is not surprising that, under certain circumstances, the reverse can also appear. The rival can stop being merely the person playing against our team and become “them”. Colours make that distinction immediately visible. The shirt, crest and scarf signal belonging. Most people keep all of this within the game, but for a minority rivalry can turn into hostility and even violence.

Intelligence invented football.

It did not invent “us”.

Our Own and the Others

Social psychology has spent decades showing how little we need in order to form groups. In Henri Tajfel’s classic experiments on the so-called minimal group paradigm, assigning people to almost arbitrary categories was enough for certain preferences toward members of their own group to emerge.

That does not mean human beings are condemned to hate strangers. Favouring one’s own group and hostility toward outsiders are not exactly the same phenomenon. We can favour our own without attacking anyone, and we can greatly expand what we consider to be “ours”.

But the ease with which we construct social categories is difficult to ignore.

It also helps explain an everyday situation. We can have far more in common with someone outside our group than with someone inside it. Two supporters of rival teams may share a profession, musical tastes, political ideas, age, friends and virtually all of their important interests. For ninety minutes, however, a completely different characteristic can take priority.

In much more extreme circumstances, something similar happens with a border.

The Stranger Who Could Have Been a Friend

War takes this capacity to one of its most terrible extremes. Two soldiers may face one another without knowing each other. Perhaps they are the same age, have young children, similar jobs and almost identical tastes. They might listen to the same music, enjoy the same books and laugh at the same things. Had they met in a bar in another country, they might have ended up talking for hours.

But they are wearing different uniforms.

One is one of ours and the other one of theirs.

At the same time, a soldier may risk his life for a comrade with whom he shares very few personal affinities. That comrade may have values, ideas or behaviours profoundly different from his own, even some he would completely reject outside that context. And yet, in that moment, he belongs to “us”. The other soldier, perhaps far more similar in tastes, character or principles, is wearing another uniform.

There are even documented cases of soldiers covering a grenade with their own bodies to protect those around them. There is no need to reduce such an extreme act to a single “group instinct”, but neither should we ignore how powerfully belonging can override other differences. Training, bonds, identity, norms and culture can reinforce a much older predisposition: protecting those we recognise as part of our group, even when doing so means assuming an enormous risk to ourselves.

Sometimes a colour, an insignia or a flag is enough to decide, at a surprisingly primary level, who belongs inside the group we protect and who remains outside. We can include unrelated individuals, even people very different from us, within a social category whose protection can come to compete with our own survival.

And our intelligence can take that capacity in two opposite directions. It can expand “us” to include millions of strangers, or shrink it until someone who might otherwise seem extraordinarily close to us becomes an enemy simply because of a symbolic boundary.

Cooperating with Strangers

Here human beings differ from many forms of animal organisation in the scale and flexibility of our cooperation.

Every morning, millions of people get into cars built by people they will never meet, travel on roads constructed with taxes paid by strangers, obey signs designed by others, buy food grown hundreds of kilometres away and use money whose value depends on an enormous community accepting the same convention.

Almost none of these exchanges requires kinship or friendship.

Human cooperation is sustained by an extraordinary combination of reciprocity, reputation, norms, trust, punishment, institutions and culture. We can cooperate with someone because we expect to see them again, because others will know how we behaved, because there is a rule we consider fair, or simply because we have learned that certain forms of cooperation are right.

Our intelligence made it possible to build gigantic societies on social capacities that evolved in much smaller groups.

But as the group grew larger, another problem grew with it.

How do we stop each individual from acting only according to their immediate interests?

The Law Against Impulse

One answer was law.

One of the most extraordinary features of our societies is that we have created explicit rules capable—at least ideally—of constraining both the person who feels an impulse and the person strong enough to act on it.

If someone hits me, I may feel an immediate urge to hit back. Society sets limits on what I can do. If someone has something I need, I cannot simply take it from them. If a person belongs to another group, they still retain rights. If someone commits a crime, even the victim must accept that a collective system will determine the response.

We do not need to assume that each of these tendencies is a separate instinct. It is enough to recognise that human beings have emotions, interests, group preferences, potential aggression and responses to threats, and that a society made up entirely of individuals who always obeyed their immediate reactions would have enormous difficulty surviving.

Laws do not prove that we have left our animal nature behind. In a sense, they show that we are capable of recognising it and building mechanisms to limit some of its consequences.

Culture does not necessarily eliminate a predisposition.

It can teach us not to obey it.

Hierarchy and Position

Something similar happens with status. Many social species organise relationships of dominance, access to resources, reproductive priority or alliances. Their structures are so different that speaking of a single “animal hierarchy” would make little sense, but attention to relative position within the group appears repeatedly in nature.

Human beings are no exception. We know who runs an organisation, who has more resources, who has prestige, who can make decisions and who receives more attention. Even in communities that explicitly defend equality, forms of reputation and recognition emerge.

Again, the difference lies in what we build on top. We can inherit titles, elect presidents, award prizes, accumulate followers on a social network or measure prestige with numbers that represent no immediate physical resource. We have turned status into another abstraction.

And then we built institutions precisely to limit it. A constitution can establish that the person with the greatest political power cannot do certain things. A law can grant the same right to someone at the bottom of the social ladder as to someone at the top.

Our intelligence did not eliminate sensitivity to hierarchy.

It invented ways to question it.

The Dog on the Other Side of the Door

There is one species in which this combination of sociability, cooperation and territory is especially visible to us because it has lived beside us for thousands of years.

The dog.

Humans and dogs come from very different lineages, but both are social animals. Over thousands of years, domestication selected animals increasingly capable of living alongside us, and today’s dogs show an extraordinary sensitivity to certain human signals. They follow pointing gestures, seek information in our faces, form attachment bonds and learn the social rules of a household.

They also understand perfectly well that spaces and groups exist. A dog may calmly accept everyone who belongs to its familiar environment and react differently to a stranger who crosses a doorway.

We make a similar distinction, although we have surrounded it with locks, doorbells, property deeds, alarms, doormen and laws against trespassing.

Part of the extraordinary ease with which the two species have learned to live together probably comes from the fact that we share two very old characteristics: we are gregarious animals and we manage territories. For a dog, it makes sense to distinguish who belongs to the group and who does not, what space forms part of its familiar environment, whom it should protect and when the appearance of a stranger may require attention or defence.

And perhaps, at a much more primary level than we like to admit, we do exactly the same.

We know who is one of ours and who is not. We know which space is ours and which feels foreign. We react when someone enters a home, threatens a member of the group or crosses a boundary we consider our own. The difference lies in everything our intelligence has built on top of that initial impulse.

The dog can mark territory with scent. We use a lock, a property deed, a flag or a border. The dog recognises those who belong to its group through coexistence, smell, voice and experience. We add surnames, uniforms, documents, symbols, anthems and shared stories. But when we react to an invasion of our space or to a threat against someone we regard as one of our own, the response can begin at a level as fast and as little deliberative as that moment when, as I fell, I held my son before I had time to decide what I ought to do.

It is not that our intelligence replaced those mechanisms with more sophisticated ones. It dressed them.

It turned territory into property, group into identity, belonging into symbol and defence into norm. Then it built arguments capable of explaining, justifying, limiting or even contradicting those responses.

But often the reaction comes first.

Perhaps part of the extraordinary success of our relationship with dogs comes precisely from there. Two social species capable of recognising group, territory, belonging and threat found a deep compatibility through domestication. They learned to read us, and we learned to read them.

We do not think alike.

But sometimes we react from surprisingly similar places.

Fear, Disgust and Survival

Not all of our ancient systems concern other individuals. Some protect the organism directly.

Fear prepares the body for a possible threat. Heart rate can change, attention narrows and the organism mobilises resources without our consciously ordering each response. Then our intelligence can use those same systems to fear things no distant ancestor could have imagined: losing a job, failing an exam, suffering an economic crisis or receiving tomorrow a piece of news that does not yet exist.

Disgust offers another example. Rotten food, certain bodily secretions, faeces or corpses can provoke rejection before we perform any microbiological analysis. It has been proposed that some of these responses form part of a pathogen-avoidance system. Other animals also show behaviours aimed at avoiding contaminated food, sick individuals or places associated with health risks.

Once again, we built on top of it.

From aversion to contamination, we moved on to hygiene rules, sewer systems, food preservation, sterilisation and medicine. A response that may have very ancient roots ends up connected to a modern laboratory.

Culture Changes Us Too

It would be a mistake to stop here and conclude that beneath a thin cultural layer there is a “true animal” that determines what we do. Culture is not decoration placed on top of biology.

It is part of us too.

From birth, we learn which behaviours are acceptable, how much distance to keep from another person, what foods we can eat, which parts of the body we show, how we express anger, whom we call family and which symbols we regard as our own. Different societies can produce very different responses from similar biological predispositions.

Cultural evolution is also far faster than genetic evolution. A norm can change in a generation. A law can change in an afternoon. A technology can alter within a few years behaviours that remained relatively stable for centuries.

Biology and culture are not adversaries. They have been changing one another for thousands of years.

Even our capacity to learn culture is a product of evolution.

Natural Does Not Necessarily Mean Good

Recognising a biological root in a behaviour does not justify it either.

This point is essential.

If aggression has evolutionary components, an act of aggression does not become morally right. If we readily favour our own group, discrimination is not justified. If jealousy, competition or territoriality exist, none of those predispositions determines how a society ought to be organised.

Confusing what exists in nature with what ought to be morally acceptable is known as the naturalistic fallacy.

Precisely because we can evaluate our own responses, we can do something extraordinary: act against them.

I can feel anger and not strike. I can feel fear and move forward. I can spontaneously prefer someone from my own group and decide to treat someone outside it impartially. I can desire revenge and accept justice.

Intelligence can find better ways to satisfy our impulses and, to some extent, allow us to decide which ones we do not want to obey.

The Animal That Built on Top of Itself

Civilisation emerged as one consequence of an animal developing extraordinarily flexible intelligence and an exceptional capacity to accumulate culture.

Social animals built cities. Animals capable of competition designed markets and rules. Animals sensitive to status invented institutions to distribute and limit power. Animals capable of aggression wrote laws forbidding its unrestricted use. Animals that protected their young built schools and hospitals. Animals that avoided disease developed medicine. Territorial animals drew borders and then signed treaties to decide how to cross them.

And an animal that distinguished its own from strangers eventually formulated an extraordinary idea: that certain rights should belong to every human being precisely regardless of the group to which they belong.

Perhaps some of the greatest challenges and possibilities opened by our intelligence lie there: understanding our nature well enough to decide what we want to do with it.

Just Another Animal

We have grown accustomed to saying “human beings and animals” as though we were talking about two separate categories.

We never stopped belonging to the second.

We still compete for resources, seek shelter, protect our young, form groups, defend spaces, cooperate, fear, desire, play and learn. We share many of these needs with animals enormously distant from us and others with our closest evolutionary relatives.

All these impulses can also be understood as part of the way evolution found, in our species, to favour the continuity of our biological inheritance. The molecule does not want to survive, think or decide anything, but variants that helped produce organisms capable of protecting themselves, protecting their offspring, cooperating with others or defending resources had a better chance of continuing. In other species, the same logic has produced different strategies. In ours, it produced, among many other things, these mechanisms that still shape a deep part of our behaviour today.

Our difference lies in the means made available to us by a particular combination of natural factors: intelligence, language, cooperation and cumulative culture.

With them, we have occupied virtually the entire planet. We have transformed ecosystems, domesticated other species, built cities visible from space, modified organisms and created machines capable of performing cognitive tasks that for a long time we considered exclusively ours.

We have even begun to imagine intelligences that may one day no longer need a biological body.

But we came from one.