I agree with Sapolsky about determinism almost entirely. He’s right about nearly everything. But there are two things that force me to reach the opposite conclusion that he does. The first is that he missed a key point about what he calls chaoticism (although a footnote on page 150 suggests that he almost caught it) and the second is that he does not appear to have any knowledge of the robust account of human psycho-social functioning provided by the science of Self-Determination Theory, which is the area of my expertise. SDT provides the account of fully functioning human beings that he admitted he was missing. But before I get to SDT, have a little patience as I set the stage. Let’s consider Bobo’s beliefs about whirlpools. Suppose that Bobo claimed that whirlpools are not real. He claims they must be illusory because Bobo, who has extensive relevant scientific knowledge, could not identify exactly which water molecules had the whirlpool feature contained within them or would otherwise decisively indicate molecular potential for whirlpoolishness. He also says that the burden of proof is on those who claim whirlpools are real. Taking Bobo’s concern seriously I would start by checking on his belief in the reality of a center of gravity. Pointing to a hoop of uniform density I would definitively demonstrate that the point indicated as the “center of gravity” is clearly NOT located in the physical material of the hoop. Does Bobo believe that the fact that a center of gravity is immaterial negate its reality? I accept a center of gravity as a real entity in the world because the concept has extraordinary predictive power. I like to say that it is fictional, but not fantastical. It is real as a conceptual tool even if it is not real in the literal physical sense of being materially instantiated. If Bobo rejects this stance then I take his attitude to be a denial of a basic feature of being human since it must logically entail rejecting most forms of money, contracts, songs, opportunities, and, many other conceptual realities that make human lives rich and meaningful.
Any reasonable person must admit that whirlpools involve water molecules but there is no way to attribute the phenomena of a whirlpool to any given water molecule. Thus, “whirlpools” are like a “center of gravity” in the sense that the word is not an indication of a static property of water such that it might be instantiated in some way in the individual molecules; it is a dynamic property that arises under very specific conditions. It is a real phenomenon in the world in the sense that it involves real physical water. However, it is an emergent dynamic property (a chaoticism in Sapolsky’s lexicon) of certain interactions between water and its surroundings. Bobo’s demand for evidence of whirlpools at the level of single molecules represents a confusion.
Back to Sapolsky, I would like to ask him about epilepsy. Is there evidence of epilepsy at the level of individual neurons? Isn’t epilepsy fundamentally a network disorder? If I claim that epilepsy is an illusion because I can’t find evidence of it in individual neurons, wouldn’t I be confused? Isn’t epilepsy, like a whirlpool, an emergent dynamic phenomenon?
Let’s get one thing clear before I continue, the term “free will” is problematic. I will allow Daniel Dennett to explain how our manifest and scientific images of the world interact:
The manifest image is the world as it seems to us in everyday life, full of solid objects, colors and smells and tastes, voices and shadows, plants and animals, and people and all their stuff: not only tables and chairs, bridges and churches, dollars and contracts, but also such intangible things as songs, poems, opportunities, and free will. Think of all the puzzling questions that arise when we try to line up all those things with the things in the scientific image: molecules, atoms, electrons, and quarks and their ilk. Is anything really solid? The physicist Sir Arthur Eddington wrote, early in the twentieth century; about the "two tables," the solid one of everyday experience and the one composed of atoms, widely separated in mainly empty space, more like a galaxy than a piece of wood. Some people said that what science showed was that nothing was really solid, solidity was an illusion, but Eddington knew better than to go that far. Some people have said that color is an illusion. Is it? Electromagnetic radiation in the narrow range that accounts for human vision (the range in between infrared and ultraviolet) is not made of little colored things, and atoms, even gold atoms, aren't colored. But still, color is not an illusion in the sense that matters: nobody thinks Sony is lying when it says that its color televisions really show the world of color, or that Sherwin-Williams should be sued for fraud for selling us many different colors in the form of paint. How about dollars? These days the vast majority of them aren't made of silver or even paper. They are virtual, made of information, not material, just like poems and promises. Does that mean that they are an illusion? No, but don't hunt for them among the molecules.
from Chapter 16 of Daniel Dennett’s Intuition Pumps and Other Tools for Thinking, 2013
It is pointless to debate “free will” as if the term is clear in a scientific sense. I use quotes around the phrase as a declaration that it cannot possibly be taken at face value due to the cultural baggage that has accrued upon it. When its use is inescapable it should be defined with reference to more precise terms that are scientifically useful. The scientifically pertinent questions regarding “free will” are about 1) the value of having a sense that we are able to control ourselves in the relevant moral way, 2) a sense of control being causally related to the patterns of behavior that are objectively observed, and 3) the idea that social processes of holding each other accountable can change patterns of behavior that are morally problematic. I propose that a “free will” worth having (per Daniel Dennett) can be derived from the primary psychological needs for autonomy and competence as used in Self-Determination Theory, founded by Edward Deci and Richard Ryan, but I’ll come back to that in a moment.
One of the key features of this conceptual move is shifting the definition of “free will” from an objective feature of the external world to a perception that is meaningful to a subjective self. This makes it obvious that it is a fool’s errand to “hunt for [it] among the molecules.” *4*
My claim that “free will” exists is based on taking the self that monitors the social environment for opportunities to gain well-being to be a real, fictional, but not fantastical, phenomena based on the book Self Comes to Mind by Antonio Damasio (for the physiological forms and functions evidence and arguments) and my knowledge of the literature on Self-Determination Theory (for more of the practical evidence of real world applicability to behavioral prediction).
To better understand how this applies I will ask you to consider a few questions. At what level of analysis does “driving” occur? Is the “driving” happening in the car or in the driver? Driving is an inherent property of neither the car nor the person sitting in the driver’s seat. “Driving” is an emergent phenomena. But it is not the same kind of emergence that arises from water in the bathtub becoming a whirlpool. Terrence Deacon has distinguished the emergence of a whirlpool from the more complex type of emergence that happened when life arose from non-living matter in his book Incomplete Nature: How Mind Emerged From Matter.
Deacon calls the whirlpool-type non-living emergence homeodynamics. What was required for life was a different level of complexity made up of more than one type of homeodynamic system that ended up interacting in ways that preserved the higher level of order that each individual system achieved on its own. Thus, this highly complex set of systems are all far from equilibrium (same as the whirlpool) yet collectively it also preserves itself through a loop of system interactions that keep all the component systems going as a single higher order system, such as a living cell or an organism. What a cell does individually and the cells in an organism do collectively is preserve the conditions for each homeodynamic subsystem to continue to exist, because it has emerged into what Deacon calls a teleodynamic system.
Teleodynamics is the level we need to talk about in order to understand driving. Teleodynamics arise out of the complex interactions among homeodynamic systems. A convergence of complex systems came together in a special way that enables the living homeostatic subsystems to preserve the arrangement of being alive, which is something we recognize as a form of purpose, though the system is not aware of having such a thing.
Let’s take a moment to be clear that mind is a consequence of teleodynamic systems according to Deacon. While Deacon did not define the term mind, I believe that Dr. Daniel Siegel’s definition of the mind as an embodied and relational process that monitors and manages flows of energy and information is consistent with Deacon’s work. Having this definition in place allows us to bring in Damasio’s idea of the self.
Damasio’s idea of the self has three parts: the proto-self, the core self, and the autobiographical self. The most basic form of self, the proto-self, is shared by almost all organisms with a nervous system that maps the body's internal state to maintain homeostasis, e.g. fish and reptiles. The core self is a transient, conscious sense of self in the "here and now" that arises when the brain maps the interaction between the organism and an object (or the world), e.g. dogs, cats, and monkeys. The autobiographical self is the most complex, language-enriched self, involving a stable sense of identity across time (past, present, and future) through extensive memory and reasoning, e.g. humans.
The self that emerged from the body-mind drives a car through the process of willing the body-car to do its bidding. The “body-car” is the relevant functional unit in anyone with more than minimal experience driving. One of the features of the self is the capability of achieving functional integration with many things that the body interacts with on a regular basis.*5* Those body-car actions are caused by a complex dynamic interaction that implicates vast networks of physical phenomena both within and beyond the body, as Sapolsky explained using different examples in his book Behave. As far as I am concerned there is no meaningful difference in explaining the causal network in a driver than there is in an insect or an amoeba, except that the driver has a consciousness that emerged out of the complexity of the feedback and feed forward loops that govern its behavior. The function of feedback and feedforward loops in all organisms is prediction and behavioral regulation based on taking that prediction function seriously. Referring to Antonio Damasio’s account of different kinds of selves, ours happens to be the kind that represents, not only the world it encounters, but also itself as a component in the world that it is simulating. This is where the notion of “free will” arises. The mind of all beings with a neurological self are prediction machines. The whole point of having a self is to make better predictions. “Free will” is our sense that our mind’s predictions matter and our choice-making is an integral part of the system of causality that determines the course of our life.
When complex systems are analyzed one of the mathematical tools for that process is the graphing of state spaces. When two or more relevant variables are portrayed as dimensions that can be graphed the result is a state space diagram. What is observed when complex systems are depicted in this way is that the system tends to fall into basins of attraction which are distinct regions within the state space. Over time the system may exhibit stable patterns within one basin but sometimes the system wanders into the far reaches of that region and becomes unstable. If the system wanders far enough, the system may tip into a different region of the state space and enter into a new pattern of stability for awhile.
What makes our minds capable of “free will” is the autobiographical self that has the added feature of representing itself in its predictions. As it monitors and modifies flows of energy and information it conceives of possibilities (different basins of attraction that the system might occupy) and makes a “choice” to favor one basin of attraction over others. In systems terms the self maps multiple basins of attraction and destabilizes the system in the hope of tipping the system into a different, more favorable, basin. If you want to find evidence of “free will” you have to be able to identify basins of attraction that the living, willing system can occupy and then figure out how the system ends up in one basin versus another. If you can identify the causal factors that determine which basin it ends up occupying then you can figure out whether “free will” is plausibly making a difference in the system. But the task of accurate prediction of complex systems is problematic, as I will discuss later.
We can directly observe the bodily interactions with the car that we call “driving.” We cannot directly observe the “willing” that directs the bodily actions. At what level of analysis does “willing” occur? Is the “willing” happening in the brain or in the mind? I believe the “willing” is an effect of the mind which is a teleodynamic emergence from brains of a certain type of complexity. According to cognitive linguist George Lakoff and philosopher Mark Johnson, “The mind is what thinks, perceives, believes, reasons, imagines, and wills” (p. 266, Philosophy in the Flesh, 1999). The mind is a dynamic emergent phenomena of the whole bodily assemblage embedded in a world, not just the brain. The mind has to be understood and analyzed at its own level in the same way that a whirlpool and epilepsy do. The self is a component of a certain kind of mind. The mind is the totality of processes that make predictions about itself, other minded things, and the environment. In the human environment there are extensions of the mind that exist beyond our bodies, e.g. cars, computers, currencies, etc. All the tools of human culture are extensions of our minds in one way or another. They extend the capabilities of our minds; those who know how to use them well are better prediction machines than those who do not know how to use them well.
What about determinism? The mind is a purely biological system that has the inherent purpose of keeping itself alive and, ideally, reproducing itself. The chemistry and physics that make up the mind are deterministic systems. The mind is an emergent property of those physical, chemical, and biological subsystems. A mind is not privy to causal information that determines what will happen in itself, nor in the environment in which it is trying to survive and thrive. If it had access to that information it might become a perfect prediction machine and it could ensure survival and reproduction perfectly. Obviously that is not what is happening in the real world.
There are four relevant ideas that help us understand our relationship to the information in the universe and how our mental concepts relate to it for predictive purposes.
- Heisenberg’s uncertainty principle in physics,
- Gödel’s incompleteness theorem in mathematics,
- the unpredictability of deterministic and simple iterative mathematical equations discovered by Gaston Julia and further developed by Benoit Mandelbrot, and
- Poincaré’s discovery that complex systems are so extraordinarily sensitive to initial conditions that they are effectively unpredictable (popularized later by Edward Lorentz as the Butterfly Effect).
I take these four findings to imply that the infamous demon with complete knowledge of the universe in a single moment still cannot know everything about it in the past and/or the future. That is not because the universe is not deterministic, but what we now know is that even a deterministic universe is unpredictable beyond some small window of time.
Sapolsky calls all this chaoticism. He has conceded that the universe is fundamentally unpredictable at some levels. I agree with Sapolsky that the mind is causally constrained by its constituent physical, chemical, and biological elements. I also agree with Sapolsky that the universe is nonetheless determined. I agree that the component parts of the mind cannot be fundamentally altered by the mind in itself, but those component parts are, crucially, capable of being constrained by the mind. There are states of those component systems that are prevented from occurring in the healthy functioning of the system. A substantial portion of energy in the form of information processing is invested in this. That kind of top down constraint is fundamental to life itself, according to Deacon. The system properties that result from that kind of constraint is what he calls absential properties.
Sapolsky also claims that if our current ignorance could be alleviated then “free will” is negated and, therefore, is merely a delusion. But I am making the point that the ignorance cannot be alleviated and, more importantly, it doesn’t matter if “free will” could, in principle, be negated by more complete information. In order to make his point Sapolsky constructs a narrative of a man who does the same wrong thing in 1922 and 2022. In the past his actions would have been attributed to “free will,” but in 2022 they would be attributed to a gene. What I suspect is wrong here is that the 2022 attribution is in error, as well. As he pointed out in a footnote, “[I]t is very rare for a single gene to be deterministic in this way. To reiterate, almost all genes are about potential and vulnerability, rather than inevitability, interacting in nonlinear ways with environment and other genes.” It may be that one person has the gene he specifies but has he accounted for the social conditions in which that person was operating? Was our criminal missing the psychological supports that might have reinforced more appropriate behavior that could mitigate against his genetic disposition? An anecdote is not data and the story of a single instance as a thought experiment does not generate an account that should be generalized to a population. Sapolsky’s story is interesting but I doubt that any gene can be as deterministic as he claims. What if we have a hundred people with that genetic disposition in a society that neglects or actively thwarts psychological needs? Through the SDT lens I would predict that more than the one deviant would be likely in a society that is pervasively unsupportive of psychological needs. In almost the same society where reform has achieved pervasive psychological need support can we expect that fewer of those genetically predisposed people would go criminally rogue? The lower rate would be caused by the way the genetic disposition interacts with psychological need supports that reinforce a "free will” worth having.
Is this story plausible? I don’t have the requisite knowledge to know whether my account of the gene-society interaction is more accurate than Sapolsky’s. One way to find out if my account is plausible is to find someone with the gene Sapolsky was referring to but did not become a criminal. If there is even one who did not, that proves the idea that the gene generates a probability, not a certainty, of criminality. The next question is whether a pervasive pattern of supporting psychological needs in the life of those with that gene is a relevant factor in its expression. My hypothesis from the SDT perspective is that more need support leads to less criminality, not just in those with that gene, but in everyone all the time.
The minds of all animals are doing their level best to be good prediction machines, but their informational limitations were determined by evolutionary processes that are not capable of tapping directly into causality. The four ideas from Heisenberg, Gödel, Julia, Mandelbrot, Poincaré, and Lorentz make it clear that we can never have the complete information necessary for making the best possible predictions. Minds, and the selves that have developed in many of those minds, are doing the best they can with the evolved mishmash of biases, heuristics, and other cobbled together neurological tricks that enabled their ancestors to survive and reproduce. The lack of causal information is an inherent limitation. Our sciences and philosophies are our best collective efforts to overcome that limitation, but they will never provide a complete understanding of the universe. They will provide enough of an understanding to accomplish many of our purposes, but the models can never be completed.
What Self-Determination Theory has revealed about our nature as humans is that our well-being is contingent upon having certain types of senses about the world and our place in it. Specifically, we have primary psychological needs for relatedness, autonomy, and competence. We cannot have well-being without these needs being fulfilled. If we agree to take “free will” to be a sloppy, imprecise way of referring to something real and important then I take it to be about autonomy and competence.
As I’ve said before, the mind is a fiction, though not a fantastical one. It is a convenient way to recognize a very specific feature of especially complex biological mechanisms. If we want to account for “free will” as a product of the mind, we need to look for evidence of it at the level of the mind. We can be confident that there is no evidence of the mind in any individual neuron, in the same way we can be confident that there is no evidence of a whirlpool in single water molecules and no evidence of epilepsy in individual neurons. In order to show evidence of “free will” we must concern ourselves with what difference it makes in behavior, since the concept is predicated on the idea that minds cause behavior. What would count as evidence in favor of having a mind with causal influence over the body? How can we account for the diversity of behavior without resorting to any magical “mind” stuff?
Let’s go back to the formation of Self-Determination Theory in the 1970s. SDT was a key component in the cognitive revolution that displaced behaviorism as the dominant explanatory framework in psychology. The fundamental assumption of behaviorism is that behaviors that get reinforced (lay people usually say “rewarded”) increase in frequency. B.F. Skinner, considered to have been one of the founders of behaviorism, was adamant that psychology adhere strictly to the scientific assumption that systematic “objective” observation be the basis for clear explanations. He insisted that the mind is a “black box” that we cannot observe directly, therefore we should not refer to anything inside that black box, such as a process like motivation or an entity like a self. Unless, of course, we have eliminated all the explanations that are more satisfying for being more objective. There are plenty of subtle nuances in behaviorism but external reinforcement is the core of behavioral research and theorizing.
Research from that time on preschool children examined what happens if you reinforce behaviors that the children do spontaneously, in the absence of prior reinforcement; behaviors such as drawing, painting, and other creative expressions (e.g. Lepper, Greene, & Nisbett,1973). The children’s artistic behaviors under reinforcement should have increased according to the central tenet of behaviorism, but what was observed was a decrease.
This was a big deal because it went against the model. There were a variety of other findings along the same lines with different populations and different activities but the crucial point is that external reinforcement alone was found to be an inadequate explanation of some specific human behaviors.
In that context Edward Deci (who did some of that research, see Deci, 1971) partnered up with Richard Ryan and they started to formulate Self-Determination Theory by synthesizing a vast literature on related ideas. Importantly, they did not reject the fundamental premise of behaviorism. They merely posited the existence of one single entity inside the black box, a self that serves as a nexus around which motivational processes are organized. The self is used to explain the oddity of how those children behaved, given how powerfully the behavioral model had successfully predicted behavior in many types of situations.
The child’s self takes in situational information outside of consciousness and based on that information alters how the child will respond to reinforcement. When the activity that is being done by the child is endorsed by the self (as spontaneous artistic expressions are expected to be), then there is maximum investment of psychic energy in that activity. The extreme version of this is known as intrinsic motivation, but in current usage within the SDT community the broader category of motivations that have positive effects on well-being are called autonomous motivations. When the activity is not endorsed by the self then there will be less investment.
The broad category of motivations that have negative effects on well-being are called controlled motivations. The key evaluative criteria that the self uses to judge situations is whether or not supports for the individual’s psychological needs are expected to be available.
The more the self expects needs to be satisfied, the more psychic energy is invested; when those needs are actually satisfied the activity is reinforced and the self is even more willing to endorse participation in that activity. It’s a positive feedback loop. When needs are thwarted then the inverse happens, forming a negative feedback loop.
Today, in SDT we understand the self-system to be responsible for the generation of psychic energy through satisfaction of needs, the transformation of energy into psychic power through motivation, and the application of psychic power to work through engagement. This is “psychic power” in an entirely non-magical biological sense. The human psychological needs for relatedness, autonomy, competence, and beneficence are presumed to be universal since cross-cultural research has been done across many societies, though more remains to be done. The first three needs are called primary since they cause well-being to be boosted when they are satisfied and diminished when they are thwarted; plus, there are about eight other criteria to establish a need as primary. The fourth need, beneficence, is secondary because it boosts well-being when satisfied, but there is no effect on well-being when it is thwarted (Martela & Ryan, 2016).
Derivative needs are a mixture of primary and secondary needs. The first need to be clearly established as derivative was meaningfulness (Martela, Ryan, & Steger, 2017). There are also particular needs that are unique to an individual, group, or culture. For example, if I were hit by a car and put on life support in the hospital I would have a whole set of needs that are based on my particular constellation of injuries.
The self takes what it expects to happen with regard to the needs and uses the energy it produces to generate some psychic power. If the needs are expected to be neglected or thwarted then the psychic power will be applied to psychological defenses. That psychologically defensive attitude exacts a cost to psychological well-being. The motivations that result are called controlled. When the needs are expected to be satisfied then the psychic power will be devoted to investing in either improving the mental maps of this type of situation, taking effective action in that situation, or most likely both. The motivations that result are called autonomous.
In the scientific SDT literature motivation is usually presented as a six part spectrum, though its details are not important here. Recently it has become more common to simplify it based on effects on well-being to a dichotomy of autonomous versus controlled motivations. Motivation has also recently been suggested to include the constructs of emotion and cognition that were previously studied as forms of engagement (Reeve, Cheon, & Jang, 2020).
So, returning to Sapolsky’s table turn on defenders of the concept of “free will” I suggest that the predictive efficacy of Self-Determination Theory provides the basis to prove that "free will,” properly understood, is a fictional, but not fantastical, means of explaining behavior. Though we do need to abandon ideas of “free will” that are not worth having, ala Daniel Dennett. I propose that we take “free will” to be a sloppy layman’s term for what the science of SDT has revealed to be our psychological needs. Sapolsky’s hard determinism is fine as far as it goes, but it has thus far failed to account for the necessity of positing the self as SDT did and the subsequent uncovering of the needs as causal factors in human well-being and behavior. There is no magic in the SDT account of how our minds use needs as predictive functions that influence behavioral choices. We can make more accurate predictions about human behavior when we take psychological needs into account as significant causal influences on human functioning.
Is holding people accountable a fool’s errand, as Sapolsky claims? According to SDT we can predict that reduced satisfaction of the needs for autonomy, competence, and relatedness are going to have negative effects on how people function. We can understand how a certain environment would lead someone to behave in dysfunctional ways. But we can also predict that in an environment properly structured to support their needs that person can use reflective tools to change their minds and the behavioral patterns that their mind leads them into. They must have senses of autonomy and competence, what might be called “free will” by some, in order to be a fully functioning human being. If we can be more technically precise than the phrase “free will” allows, we can shape our systems of education, law, and politics to produce far better outcomes than they do now. However, denying the reality of “free will” would be a grave mistake if it leads to structuring society in ways that will tend to thwart psychological needs rather than support them. We need to reframe that term as a sloppy version of what has been revealed by science about the psychological needs.
Let’s be clear that we are ultimately concerned with the predictability of behavior in the sense that we want to create conditions in which people can effectively will themselves to do good. Our fundamental worry is that people are sometimes ineffectively willing good and accidentally doing bad instead, or worse that they will themselves to do bad things.
The key is that we are all assuming that behavior is both predictable and changeable. We just need to know how to set up the environment to get the kinds of good behavior that we want. I agree with Sapolsky that no one deserves anything— we are not god, so we have to be extremely careful when we assign god-like powers of judgment to some people. Unfortunately, we know that external contingencies in the behaviorist mold are not as effective as we would like them to be. SDT has shown that mere external contingency operations are ineffective because they fail to account for the human self that alters the effects of reinforcement. We can do much better by abandoning the sloppy layman’s term “free will” and using the technical understanding that has been developed since the 1970s under the SDT banner to better understand the mind’s influence on behavior. In the sense that the physical universe is deterministic we must understand that our minds, selves, and “free will” are all fictional, but not fantastical entities. We all have minds with a self that is looking out for us. They do that important work by attending to our needs. The mind has been attuned by evolution to keep track of how it might be manipulated by others in ways that could undermine our well-being. Ultimately, we need to recreate our institutions of learning and behavioral accountability to reflect this technical understanding of our nature as human beings with the needs for relatedness, autonomy, competence, and beneficence.
Resources
Blakesley, S. and Blakesley, M. (2007) The body has a mind of its own. Random House, Inc.
Damasio, A. (2010). Self comes to mind: Constructing the conscious brain. New York, NY: Pantheon Books.
Deacon, T. W. (2011). Incomplete nature: How mind emerged from matter. W. W. Norton & Company.
Deci, E. L. (1971). Effects of externally mediated rewards on intrinsic motivation. Journal of Personality and Social Psychology, 18(1), 105–115. https://doi.org/10.1037/h0030644
Dennett, D. (2014) Intuition pumps and other tools for thinking. W.W. Norton & Company.
Martela, F., & Ryan, R. M. (2016). “The Benefits of Benevolence: Basic Psychological Needs, Beneficence, and the Enhancement of Well-Being.” Journal of Personality, 84(6), 750–764. https://doi.org/10.1111/jopy.12215. Note: This paper does not present the evidence that downgraded beneficence to a secondary need; I heard the news when Richard Ryan announced it from the stage at the 6th International Self-Determination Theory Conference in 2019.
Martela, F., Ryan, R. M., & Steger, M. F. (2017) “Meaningfulness as Satisfaction of Autonomy, Competence, Relatedness, and Beneficence: Comparing the Four Satisfactions and Positive Affect as Predictors of Meaning in Life.” Journal of Happiness Studies. Advance online publication. https://doi.org/10.1007/s10902-017-9869-7.
Lakoff, G., & Johnson, M. (1999). Philosophy in the flesh: The cognitive unconscious and the embodied mind: How the embodied mind creates philosophy. New York, NY: Basic Books.
Lepper, M. R., Greene, D., & Nisbett, R. E. (1973). Undermining children's intrinsic interest with extrinsic reward: A test of the "overjustification" hypothesis. Journal of Personality and Social Psychology, 28(1), 129–137. https://doi.org/10.1037/h0035519
Paul, A. M. (2021). The extended mind: The power of thinking outside the brain. Houghton Mifflin Harcourt.
Reeve, J., Cheon, S. H., & Hang, H. (2020). Reconceptualizing the student engagement construct to increase its explanatory power. Contemporary Educational Psychology, 62, 101899. https://doi.org/10.1016/j.cedpsych.2020.101899
Sapolsky, R. (2017) Behave: The biology of humans at our best and worst. Penguin Books.
Sapolsky, R. (2023) Determined: A science of life without free will. Penguin Books.
