The Evolution of Agency Michael TomaselloI thought developmental and comparative psychology professor Michael Tomasello’s 2019 book Becoming Human: A Theory of Human Ontogeny was brilliant and rigorously argued. Imagine my surprise to find the first three chapters of this short work (164 pages) practically insulting because of sloppy writing and terminological vagueness.

As a result, I decided to call it a day – even though, admittedly, the remaining chapters (about the agency of apes and humans) might play more into Tomasello’s strengths as a researcher. I guess it’s my loss – 32.48 euros to be precise – but I cannot but operate using inference if I read scientific books: if your base is brittle, I’m not going to risk dwelling in a superstructure that seems solid. It’s a form a prejudice, yes, but my time is limited, and there’s way too much else to read & learn.

Even if I didn’t read it completely, I do have a few thoughts and criticisms to offer, and I hope this review will offer some food for thought.

For starters, let me quote the blurb from MIT Press, so that you know what the book is about:

Nature cannot build organisms biologically prepared for every contingency they might possibly encounter. Instead, Nature builds some organisms to function as feedback control systems that pursue goals, make informed behavioral decisions about how best to pursue those goals in the current situation, and then monitor behavioral execution for effectiveness. Nature builds psychological agents. In a bold new theoretical proposal, Michael Tomasello advances a typology of the main forms of psychological agency that emerged on the evolutionary pathway to human beings.

Tomasello outlines four main types of psychological agency and describes them in evolutionary order of emergence. First was the goal-directed agency of ancient vertebrates, then came the intentional agency of ancient mammals, followed by the rational agency of ancient great apes, ending finally in the socially normative agency of ancient humans. Each new form of psychological organization represented increased complexity in the planning, decision-making, and executive control of behavior. Each also led to new types of experience of the environment and, in some cases, of the organism’s own psychological functioning, leading ultimately to humans’ experience of an objective and normative world that governs all of their thoughts and actions. Together, these proposals constitute a new theoretical framework that both broadens and deepens current approaches in evolutionary psychology.

Before I’ll discuss the book itself, it is of note that the blurb makes a curious distinction in the very first lines. Aren’t these organisms that have “feedback control systems” biological? Aren’t these systems itself biological? Didn’t these systems evolve biologically? I can’t fully put my finger on it, but I have the feeling this is the crux of the matter at hand, and the conceptual quagmire on which Tomasello builds his theory, the ontological reason for his vagueness and his at times muddled thinking. I’m sure the last sections of the book on human social normative psychology won’t suffer as much from this problem as his first chapters – if they even suffer from it at all – but if you present your book as an evolutionary account, you better start it right.

Anyhow, the remainder of this text consists of a few thoughts and examples that are in no way an attempt at a full critique or discussion of the parts of the book I did read.


It starts with an unclear conception of ‘agency’ itself:

“Agency is thus not about all of the many and varied things that organisms do – from building anthills to caching nuts – but rather about how they do them. Individuals acting as agents direct and control their won actions, whatever those actions may be specifically. The scientific challenge is to identify the underlying psychological organization that makes such individual direction and control possible.”

It seems to me that the real scientific challenge is to identify the underlying neural pathways that guide our muscles to perform specific behavior. Tomasello is not clear at all about what “psychological” entails, and how that ties into neurology, biology & evolution. I would advice him to read 2019’s brilliant The Evolution of the Sensitive Soul: Learning and the Origins of Consciousness of Simona Ginsburg & Eva Jablonka for an example of how a true, rigorous scientific account of the evolution of agency could be written. It also struck me that Tomasello often names learning as crucial in his early chapters – thus confirming at least a part of Ginsburg & Jablonka’s thesis – but not once does he engage with the biological pathways of learning, nor how these neural pathways might have evolved.

A bit later in the book agency turns out to be about the capability of “choosing to act or not to act, or among multiple possible actions, according to its continuous perceptual assessment of the situation as it unfolds over time (sometimes employing executive processes such as inhibition, as a further control process, during action execution).” This is equated with behaving in “psychologically agentive ways”. The biological (neural) nature of ‘choice’ is sadly left unexamined.


The book is full of modifiers like ‘mostly’ and ‘to some degree’, but then fails to conceptually zoom in on what this actually means for the theory at hand. E.g., page 6:

“Tomesello and Call (1997) explicitly stated that things such as spiders building spiderwebs are interesting and complex phenomena, but they are not psychological, precisely because they are mostly not under the individual spider’s flexible control. The concept of agency thus, in a sense, represents the dividing line between biological and psychological approaches to behavior; it is the distinction between complex behaviors designed and controlled by Nature, as it were, versus those designed and controlled, at least to some degree, by the individual psychological agent.”

Note the words & phrases “mostly”, “in a sense”, “at least to some degree” and “as it were”. Tomesello never specifies these further. Surely it is conceptually very important in which way the individual spider does flexibly control its weaving, as is implied by the use of the word “mostly”? Again, the dividing line between biology and psychology might be clear to Tomesello himself, but he doesn’t manage to make it clear to the reader. At one hand, it seems to be something binary, a dichotomy (“a dividing line”) but at the same time it isn’t (a matter of “degree”).

Another example of this page, on the wormlike C. elegans, page 29:

“However, it is unlikely that there is also a comparison with some kind of internal goal to create direction: their locomotion is mostly random or stimulus driven. And these organisms do not seem to exhibit anything that we would want to call behavioral control: they do not inhibit or otherwise control action execution, and what they learn is simply the location toward which to direct their hardwired movements.”

For starters, again, “mostly”? I would like to know more on that. Second, if they learn to direct themselves to food, at least part of their movements is not “hardwired” anymore, but goal directed, I would say. Tomasello never goes into the nuts and bolts of the distinction between goal-directed behavior, and stimulus driven behavior.

It seems to me an internal goal (possibly accompanied by a conscious mental representation, as sometimes in humans) is a stimulus too. The fact that it is a stimulus originating from the neural systems inside the body does not feel so conceptually different from a neural stimulus that originates outside the body, as it only matters for the onset of the stimulus, not the resulting neural paths inside the body, i.e. not for the processing of the signal. Again, as for stimuli and different kinds of learning, I’d rather read another painstaking tome like that of Ginsburg & Jablonka, than this short, breezy book.

When Tomasello also admits that this worm also knows how to avoid noxious chemicals, doesn’t it have some kind of “inhibition” too, and thus forms of action control? What’s the difference with the “feedback control organization” he talks about on the next page?

By the way, is the phrase “we would want to call” (my italics) a telltale?


Tomasello seems to think that “psychologically agentive species” somehow escape mechanic (neurological) pathways. He seems to forget that everything that happens in the brain, the neural system and the body is the result of molecular structures, molecular movement & energetic signals. Is he a closet Vitalist?


It seems to me that behavioral flexibility has not so much to do with agency, as Tomasello has it, but with the capacity for learning. Again, see Ginsburg & Jablonka.


On lizards, Tomasello introduces the concept of “go-no-go decisions”, page 39:

“Nevertheless, despite functioning as flexible decision-makers, goal-directed agents can make only simple decisions. They do not survey and choose among multiple behavioral possibilities simultaneously but rather move sequentially from one go-no-go decision to the next. This is to be expected of an organism whose behavior emanates exclusively from the single psychological tier of perception and action, rather than from, in addition, an executive tier of decision-making and cognitive control that formulates multiple action plans and then decides among them before acting, as do more complex agents.”

My question here is what happens when a lizard perceives two fat insects slowly hovering in place withing reach at about the same distance at the same time?

In the same chapter part of Tomasello’s reasoning hinges on the fact that lizards might learn to eat a new insect because of “behavioral agency”. It seems to me this kind of behavior has not a lot to do with agency at all. Why do lizards try to eat new insects? Simply because they resemble other insects. They have about the same size, they buzz, they have wings, they have six legs, etc. It seems to me that eating a new kind of insect is not new behavior at all, just the same behavior that operates on a slightly different kind of real world input (an hitherto unmet insect presents itself to the lizard), of which the slight difference does not matter to the lizard’s internal decision process, more so, the lizard might not even register that slight difference. It’s like certain geese that have been observed to roll back beer cans to their nests because they think the can is one of their eggs. Behavioral agency!

Because of examples like this, I decided to abandon the book 25% in. A go-no-go decision, or a form of inhibitory control? Either way, I’m pretty sure it wasn’t a form agency: the decision kinda forced itself through my eyes into my brain.

One brilliant quote though: “The straightforward implication is that organisms that behave differently experience the world differently.

If you’re interested, Tomasello basically summarizes his book in about 48 minutes in a YouTube talk – clearly indexed – with Ricardo Lopes on The Dissenter. At the end, he admits to being simple-minded by first relying on a psychological self-report argument, and then simply equating having the capacity to “[make] choices” to having a “free will” that is not “determined”. Bonkers really, the level of sophisticated thought displayed by a Duke professor – but indeed, he can’t help it.

Click here for an index of my non-fiction reviews. Here‘s an index of my longer fiction reviews of a more scholarly & philosophical nature. Here are my favorite lists – including a list of favorite non-fiction.

The author index includes all my fiction reviews – most of it science fiction.



  1. Sorry you had to spend so much money only to deal with that kind of outcome.

    I think your decision to dnf was simply your destiny. It was pre-ordained 😉
    On a serious note though, any “scientific” book that uses the terms you mention (mostly, perhaps, etc) really stops being a scientific book and becomes more of an Op/Ed piece written by an intelligent person.

    Liked by 1 person

    • I agree very much about it being my destiny.

      On the money front, it is actually infuriating how academic non-fiction books are priced: much higher than fiction books, while the academic authors don’t need to live of the sales of their books, but fiction authors do. Academic authors get a salary from their institution. So the high price is the publishers making money, basically leeching of public funding or patronage, as most buyers of academic literature are libraries and academic institutions that get their funding from the state and/or patronage.

      Liked by 1 person

  2. I understand your criticisms of this book, and I think I agree with them. It is basically impossible to make a clear distinctions between these four types of agency that he has come up with. It’s an interesting theoretical framework but impossible to test or explore. When is behavior the result of what behavioral biologists call “instinct” and when is it some higher level of conscious or rational agency? We famously no do know what it is like to be a bat. And then we enter the quagmire of phenomenology and qualia and so on.

    Liked by 1 person

  3. Capacity for learning is so important. Our willingness to know ourselves may be the hardest to do.

    Liked by 1 person

  4. Of course, it is impossible. Because we are learning forever just as we are always in the process of evolution too. To me these two are inexhaustive…


  5. Behavioral flexibility has not so much to do with agency, as Tomasello has it, but with the capacity for learning.

    – which I guesss would be tied into intelligence? The more intelligent a particular animal, the more it can learn, the more nuanced its decision-making.

    I’d really just see this as a spectrum, further qualified by how – at least, as far as Mother Nature is concerned – human beings don’t behave very differently from any other living thing; they fight over resources/territory, mate, reproduce, rear their young and die.


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  7. Becoming Human was one of my favourite non-fiction reads of the last few years, I felt like it gave me some building blocks to make my worldview more complete… and I read it solely based on your recommendation, so I’ll follow your advice here as well 🙂

    Liked by 1 person

    • I understand what you say, I feel similar, indeed somehow a foundational book. The Jablonka & Ginsburg felt bit the same for me. I think Tomasello simply bit of more than he could chew: he’s simply not an evolutionary scientist.

      Liked by 1 person

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