Be warned, this one is a blockbuster: just one main blog item, considerably longer than usual and it will help a lot if you put your thinking cap on and take it at a gentle pace. Actually, the ideas involved are fundamentally quite simple but you will need to pay attention if most of this stuff is new to you. What’s it about? It’s a reflection on the work of Robert Trivers, a pioneer of evolutionary psychology who died recently. It’s a discipline often dismissed by Foucault fans (of whom I am one) on what I believe are misconceived grounds. What follows is my attempt to describe Trivers’ main theoretical insights and share my enthusiasm for them.

The significance for MAPs is not my main focus but it certainly exists because the work is fundamental to sexuality in general. It would be great to have some feedback on your thoughts about this. In general, Heretic TOC is fortunate to routinely attract comments running into three figures, many of which are of high quality and do a wonderful job in keeping us up to date with new research and MAP news. On this occasion, though, I would make a plea for more comments about the actual blog itself. Don’t be afraid to argue with me. I want to learn from dialogue with you all.

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Not to put too fine a point on it, Robert Trivers, whose reflections on the origins and basis of human psychology – including sexual motivation – dug deeper than even those of Darwin or Freud, was a bit of an asshole.

Trivers, who died last month, was arrogant, boorish, unreliable, unpredictable, in thrall to wild excess, and even downright thuggish. As a leading columnist told us,

His bizarre memoir Wild Life is not the place to turn to in order to learn of his brilliant ideas. It is mainly the story of his arrests, of his friends being murdered, of him being involved in knife fights, of getting an ice pick stabbed through his hand in a nightclub and of the various moments when his cocaine or marijuana stash was fortuitously missed by suspicious police officers… He loved the murderous African-American criminal Huey Newton and joined his thuggish Black Panthers. Most recently, he has been revealed as (of course) a good friend of Jeffrey Epstein. – Daniel Finkelstein, The Times, 25 March 2026

Ah. Yes. Epstein. Well, as readers of my previous blog will know, there are things to be said in Jeffrey’s favour. But Danny, bless him, aka @Dannythefink, perceptive and good-hearted man though he undoubtedly is, cannot be right about everything. He is, after all, Lord Finkelstein, a Conservative peer.

Moving swiftly on, the eminent psychologist Steven Pinker has pointed out in Quillette that Trivers’ early scientific work included researching lizards in Jamaica. He stayed for many years, in a life of boozing, brawling and whoring. He married two Jamaican women (not at the same time, but no one would have put it past him) and said he found the girls there so hot he needed no other reason to be on the island.

But we have another reason to think about him. As Pinker reminds us, Trivers the scientist has given us insights that are quite simple once they are explained, but eluded great minds for ages. In a brief creative burst from 1971 to 1975, he wrote five seminal essays that invoked patterns of genetic overlap to explain each of the major human relationships: male with female, parent with child, sibling with sibling, partner with partner, and individuals with themselves – not in the physical “self-love” or masturbation sense, but in the stories we tell ourselves, especially as regards our capacity for self-deception.

Full disclosure: in what follows I will be using Pinker’s account extensively as a crib sheet. I have no wish to plagiarise, which is a dishonest practice that unfairly takes the credit for another person’s work, passing it off as one’s own. I do the opposite. I pay homage to Pinker, whose clear description invents the wheel, if you will, and I see no reason to reinvent it with my own rickety spokes and rims more hexagonal than circular.

That said, I no not intend to be Pinker’s slavish devotee. Like Finkelstein, Pinker leans to the right, as do a good many enthusiasts for the evolutionary psychology we will be discussing. It cannot be stated too strongly, though, that there is nothing intrinsically right-wing about the science in question. How could that be the case when, as will be seen, Trivers explores the deep origins of our ability to cooperate with each other, not just ruthlessly compete, as in winner-takes-all capitalism? How could evolutionary psychology be intrinsically right-wing given that it reveals our sense of fairness and justice is based on a firm foundation, and also grounds our profound belief that equality is a key concept (as with socialism) underpinning these ethical perceptions?

In the wake of Foucault, social constructivist thought on the Left has rightly tended to be sceptical of science, dismissing its claims to objectivity as bogus and noting its suspicious corruption in the service of paymasters that include the Military Industrial Complex, Big Pharma, and the now global Child Protection Racket. Nevertheless, it would be foolish and futile to deny that science can be hugely impressive – often difficult to harness safely, admittedly, as with nuclear power or AI, but that is testimony to its reality and potency. It means that if you study chemistry and biology in school you will genuinely be starting to learn how stuff actually works. It’s not just bullshit – which is more than can be said for a lot of what passes as postmodern scholarship these days.

The influence of Trivers’ work on science was vast. His ideas took pride of place in E O Wilson’s Sociobiology in 1975, Richard Dawkins’ The Selfish Gene in 1976, and many other landmark contributions in the next three decades such as Robert Wright’s The Moral Animal (1994) and Pinker’s own The Blank Slate in 2002. The implications for everyone were immense, as Pinker says:

The insight that partial genetic overlap among individuals leads to both confluences and conflicts of interests explains why human life is so intricate – why we love, and bicker with those we love; why we depend on one another, and mistrust those we depend on; why our emotions are powered by moral themes and not just physical threats; why deluded people are certain of their convictions and evil ones convinced of their rectitude.

The ground for Trivers’s revolution had been laid in the 1960s by George Williams and William Hamilton, who focused on the key fact that natural selection is driven by competition among “replicators” (i.e. the basic units of evolution, called “genes” in biology, although other kinds of self-replication are possible, notably “memes” – a term coined by Dawkins – which are culture’s way of making things “go viral”). This implies that the beneficiary of evolutionary adaptations is not the group or even the individual, but the gene. Hamilton drew out an implication: genes can perpetuate themselves by nurturing not only offspring but siblings and other kin, since any genes that benefit a blood relative would, with a certain probability, benefit copies of themselves in the bodies of those relatives. 

Trivers’s innovation was to show how the partial overlap of genetic interests between individuals should put them in a partial conflict of psychological interest. The key resource is parental investment: the time, energy, and risk devoted to the “fitness” of a child. Pinker uses this word without any quote marks or explanation, which may lead readers unfamiliar with the technical use of the term to think he is talking about our physical condition, as in “he is as fit as a fiddle” or “fit as a gym bunny”. But what biologists mean is much more inclusive. Yes, it’s about being in good shape, but it’s also about being smart; it’s about your chances of surviving into adulthood with a good chance of having your own children, thereby passing your genes into the next generation. He is talking about the survival of genes over thousands of generations, from when we were all hunter-gatherers, living a very different lifestyle to now, in what is sometimes called “the ancestral environment”. Known to evolutionary psychology more technically as the Environment of Evolutionary Adaptedness (EEA) this was the environment that shaped our brain and the psychological inclinations and desires it harboured, including our feelings about mating, parenting, and social relationships.

It may also seem odd or even obnoxious to use the term “investment”, as though parenting were a capitalist enterprise rather than a labour of love. This sort of language has unfortunately misled many of us gentle, kind, herbivorous lefties into supposing the psychologists who use it must be callous swine in white coats who cold-bloodedly see the whole of humanity as merely self-serving and ruthless. Even Dawkins’ provocative title The Selfish Gene inadvertently took us quite a way down that road, which he later regretted, along with other aspects of his eloquently arresting style. Ironically, he wrote too well for his own good!

Nevertheless, the concept of parental investment is a truly powerful and necessary one for anyone who wants to understand why we are as we are. What follows, based on Pinker’s summary of Trivers’ foundational work might seem far-fetched and (if you are versed in the standard objections) “reductionist” or “essentialist”, or “genetically determinist”, but my advice is don’t knock it before you really understand it. The name may be Trivers, folks, but he ain’t trivial, and his understanding ain’t superficial, so listen up and listen good. Pinker again:

Parents have to apportion their investment across all their children, each equally valuable (all else the same). But although parents share half their genes with each child, the child shares all its genes with itself, so its interest in its own welfare will exceed that of its parents. What the parent tacitly wants – half half for Jack, half for Jill – is not what Jack and Jill each want: two thirds for the self, one third for the sib. Trivers called the predicament parent-offspring conflict. Its corollary is sibling-sibling conflict: every offspring has an interest in its siblings’ welfare, since it shares half its genes with the sib, but that interest is outweighed by the twofold genetic interest it has in itself. 

Jill may not even exist yet for Jack and his parents to differ over her welfare. Baby Jack may want to suck his mother dry, while Mom wants to keep part of herself in reserve for unborn Jill and other future offspring. The conflict is waged throughout the lifespan: in ailments of pregnancy (like pre-eclampsia and gestational diabetes), postpartum depression, infanticide, cuteness, weaning, brattiness, tantrums, rebelliousness, sibling rivalry, and struggles over parental attention, support, and inheritance.

Not that toddlers are ever consciously battling on behalf of their own genes, of course, and especially not in the mathematically exact and calculated way that Pinker’s words might suggest. Rather, it makes more sense to think of these calculations as the scientists’ way of bringing precision to bear on what drives us unconsciously, by instinct.

It may help to consider sibling rivalry for a moment, which Pinker mentions above. Unlike parental investment, this is a scientific concept that is also familiar in everyday language and life. Unless we are an only child, most of us will have experienced it directly with our own brothers or sisters. Often it can be quite extreme, leading to bitter and toxic quarrels in childhood, sometimes leading to a lifetime of enmity and resentment, especially when there is much at stake in rich and powerful dynasties, fighting over who will inherit the crown or the business empire. Such has been the stuff of legend from the Bible’s Cain and Abel, or Isaac and Ishmael, to Game of Thrones and Succession in our own day.

My older Big Brother and I were too far apart in age (six years) for intense rivalry in childhood. He was so clever, sophisticated, strong, and athletic there was just no contest. He was awesome to me and my parents alike. I hero-worshipped him. If there were to be a battle between us over who was more worthy of parental investment in our future, he should have won hands down.

Except it wasn’t that simple. Bro was actually quite jealous (as he confessed to me decades later) because I somehow stole a lot of parental attention. Part of it was inevitable of course. I can claim no personal merit whatever in being younger and smaller, which automatically made me cuddlier and cuter! But additionally, unlike my slightly too self-assured and rebellious brother, I was also pleasantly “low maintenance” for Mum and Dad. Bro must have been heartily sick and tired of hearing how I was no trouble at all, a Little Angel! Looking back, there must have been times when he could cheerfully have murdered me. Well, thanks, Bro, for not yielding to that temptation! Until he died a few years ago we remained in wary but amicable correspondence with each other, and he will always be my hero.

What we had each managed in childhood was to win parental investment through different self-marketing strategies: Bro’s fitness in evolutionary terms was never in any doubt. He was an Alpha male all the way. So instead of trying to compete by being fitter in the crude understanding of the “survival of the fittest” – tough, and dominant – I found myself slotting smoothly into a different evolutionary niche, that of a useful, well functioning, Beta male. Rather than making my mark as a leader, I would be the “nice” sibling, adorable as a kid and seen by Mum and Dad as a gentle and cooperative child, and also one with a viable future. They could be confident I would become a reliable worker, the sort of loyal team player employers are keen on. Fit, as it were, for survival in the workplace.

Or if I were to be any sort of leader it would be in some sort of “caring” occupation, or a quietly scholarly role – I was always “bookish” enough to suggest that possibility. Mum often called me “my little professor”, and once she told me she thought I might become a missionary, taking Christianity to the empire Britain still had in those days, perhaps even becoming a bishop! She also thought I would make a good husband and father one day. Plenty of girls would love a “steady earner” – a nice, regular guy who would stick around though thick and thin and be great with the kids. Genetic mission accomplished!

Well, things don’t always go to plan, do they? A key take-away is that just as weather forecasts these days are based on scientific observations and modelling but are still not entirely reliable, neither are predictions about people. There are just too many variables, including random unknowns. Our futures are not determined by our genes, only influenced by them. This doesn’t mean evolutionary psychology is useless bollocks. We would be foolish to ignore its insights, just as no wise mariner would ignore a storm warning.

Parental investment, Trivers explained, is also implicated in the battle of the sexes. When Darwin introduced the concept of sexual selection, he observed that in most species, males compete and females choose, but he had no idea why. Trivers explained the contrast by noting that in most species the minimal parental investments of males and females differ. Pinker again:

Males can get away with a few seconds of copulation; females are on the hook for metabolically expensive egg-laying or pregnancy, and in mammals for years of nursing. The difference translates into differences in their ultimate evolutionary interests: males, but not females, can multiply their reproductive output with multiple partners. Darwin’s contrast can then be explained by simple market forces. And in species where the males invest more than the minimum (by feeding, protecting, or teaching their offspring), males are more vulnerable than females to infidelity (since they may be investing in another male’s child) and females are more vulnerable to desertion (since they may bear the costs of rearing their mutual offspring alone). 

In another landmark, Trivers turned to relations among people who are not bound by blood. No one doubts that humans, more than any other species, make sacrifices for non-relatives. But Trivers recoiled from the romantic notion that people are by nature indiscriminately communal and generous. It’s not true to life, he thought, nor is it expected. Instead, he noted, nature provides opportunities for a more discerning form of altruism, in which there is an exchange of benefits. One animal can help another by grooming, feeding, protecting, or supporting them, and is helped in turn when the need arises. Everybody wins. 

Trivers called it reciprocal altruism, and noted that it can evolve only in a narrow envelope of circumstances. That is because it is vulnerable to cheaters who accept favours without returning them. The altruistic parties must recognise each other, interact repeatedly, be in a position to confer a large benefit on others at a small cost to themselves, keep a memory of favours offered or denied, and be impelled to reciprocate accordingly. Reciprocal altruism can evolve because cooperators do better than no-cooperators. They enjoy the gains of trading surpluses of food, pulling ticks out of one another’s hair, saving each other from drowning or starvation, and babysitting each other’s children. Reciprocators can also do better over the long run than the cheaters who take favours without returning them, because the reciprocators will come to recognise the cheaters and shun or punish them. 

Reciprocal altruists must be equipped with enough brain power to recognise and remember individuals and what they have done. That helps explain why Homo sapiens, the most social species, is also the smartest one; human intelligence evolved to deal with people, not just predators and tools. We must also be equipped with moral feelings that implement the tit-for-tat strategy necessary to stabilise cooperation. Sympathy and trust prompt people to extend the first favour. Gratitude and loyalty prompt them to repay favours. Guilt and shame deter them from hurting or failing to repay others. Anger and contempt prompt them to avoid or punish cheaters. 

Language has played a distinctive and critical role in this reciprocal altruism. Because we are language users, any tendency of an individual to deal fairly or cheat, lavish or stint, will quickly become known to others. Quite literally, word will soon get around about their reputation. And because our reputation affects our ability to secure favours (it is all about our credibility and “credit rating”, stretching from our buddies to our bankers) it will be in our interests to have a good reputation. Most of us find the easiest way to do that is to pay our bills and buy our round at the pub without trying to wriggle out of such obligations at every opportunity.

But that’s not the end of the story. The most profound aspect, Trivers’ greatest discovery, is where he goes next. We are all familiar with the notion that we sometimes fool ourselves. Self-deception, like sibling rivalry, is a frequent theme in literature, especially the potentially tragic consequences of failing to “know thyself”, as in Shakespeare’s King Lear. What Trivers uniquely added to the story is how self-deception evolved, and how it can work to an individual’s advantage rather than always ending badly. Indeed, unless it conferred some benefits it would be hard to explain why so many humans have become so good at it: if the consequences were always tragic, those who routinely deceived themselves, becoming completely detached from reality, would have been seen as idiots, or crazy. They would never have found sexual partners who wanted to have children with them, and any genes promoting the self-deception trait would have died out.

The best thing of all (from an evolutionary standpoint) would be to get people to help us without returning their assistance, but also without damaging our reputation. So as well as developing a co-operative instinct, we also evolve the capability to deceive other people with lasting success.

This, Trivers realised, led to two further steps in evolution. The first is that we develop strategies for spotting this deception. Second, we develop even more sophisticated methods to ensure our deception evades detection. This escalating arms race between deception and detection culminates in the supreme form of deception. We deceive ourselves.

Danny Finkelstein tells us that Trivers, in his book The Folly of Fools (2011) explains that when we knowingly lie and deceive we often worry about being caught out, and our nervousness gives us away. Other people can see through it. They are watching keenly because they have evolved to watch keenly. So we have evolved, in retaliation, a way to avoid being caught out: we deceive ourselves. Then, a stray glance or a nervous move won’t let us down. If we truly believe we are being honest, we will be able to look others straight in the eye and speak with passion and conviction.

This routinely works brilliantly for the ardent young man with an ’ardon, eager to get a chaste girlfriend’s knickers down. All he needs to do is believe he loves her, he’d died for her, he’ll be hers till the end of time, till the stars cease to shine… That strength of belief comes all too naturally for many guys, even if “the end of time” turns out to be the end of the month, or whenever the first quarrel or inconvenience comes along. If it’s that shallow, of course, reputation will ultimately suffer, but there are plenty of entirely sincere serial Prince Charmings for whom it always works like a charm.

My first encounter with this theme would have been way back in the 1970s when I read The Selfish Gene. Trivers wrote a foreword in which he included a couple of sentences on self-deception. I have no memory of this (Pinker’s article reminded me) and I am sure the significance of a brief few lines would have escaped me at the time.

Much more important to me was the appearance of Wright’s The Moral Animal a couple of decades later, which gives an extensive account of Trivers’ insights, especially how the simple basis of reciprocal altruism (“You scratch my back and I’ll scratch yours”) grew into deep moral convictions as to what constitutes fairness and justice, underpinning not just personal exchanges of favours but also much bigger concepts, such as the Golden Rule (“Do as you would be done by”), the Rule of Law, and even the high concept of Human Rights.

When I encountered Wright’s book in the 1990s, it struck me as the most profound non-fiction work I had ever read, beating Darwin, Freud, Marx, you name it, and leaving even great poetry, drama and novels struggling to match its meaning for me. Would I still recommend it today? Absolutely, except for the fact that genetics has taken giant leaps forward in recent times. Trivers’ insights are still valid (just as Darwin’s are still foundational) but these days I would choose a book, or perhaps a few expert podcasts, that goes into the co-evolution of genes and culture. No serious scholar would claim these days that the human story is just about either the genes we inherit or the culture we grow up in, shaping our learning and behaviour. The story is one of both/and not either/or.

On that basis, I am guessing the best fairly recent book would be The Ape that Understood the Universe: How the Mind and Culture Evolve, by Steve Stewart-Williams, 2019. I haven’t read it yet, but the publisher’s description and expert reader recommendations make it a tempting one to put on my list to get around to. I’d love to hear from any heretics here who know this book already and can give us their verdict, or make other recommendations.