Emotions Measure & Motivate

And a story about an iguana.

When I was in college, my sister was only seven years old and she, in turn, had a pet iguana. One summer day between my freshman and sophomore year, my little sister asked a really dumb question which was so clever it haunted me for the next quarter of a century or so: How does Iggy (the iguana) know what to do?

What’s an iguana to do? (Created with DALL-E)

My first instinct was to channel my inner cabdriver from Catcher in the Rye and allow as to how it did what it did because “it’s their nature, for Chrissake.”^[1]

But I had taken just enough philosophy classes by that point to know that wasn’t, really, an explanation. Why was that his nature? And what was this nature, exactly? How did it know what to do? The iguana could, I supposed, do any number of things at any given moment. Usually what it decided to do was sit on the electric rock and eat leaves. Out of its options – limited, true – why, and how, did it pick those? And what about iguanas in the wild, whose options ranged far beyond those available to Iggy? Out of their plentiful options, how did they know what to do?

I can’t say for sure that iguanas are conscious in the way that you and I are, but the proposal I offer here applies as much to iguanas as to people. The keys to understanding how organisms – with scales or without – choose what to do are, I argue, measurement and motivation.

The basic idea stems from the theme of this project, that people’s motives can be explained with reference to evolution. The crux of it is this: to behave adaptively, we – and iguanas – need to be able to measure many different parts of our worlds, both internal and external. To know how urgent it is to move your hand, you have to measure if, and how much, it’s currently being damaged by the fire. To know how urgently you should prioritize visiting a restroom, the space left in your bladder needs to be measured. These examples illustrate the general principle: to respond appropriately – adaptively – to any threat or opportunity, the threat or opportunity must be detected and measured.

Now, once you have a measurement, that measurement – how much heat, how much remaining volume – motivates decision-making and action.

Now, somewhere in the middle there, between the measurement and the motivation—well, that’s where the magic happens.

Because the singular thing about the heat of the fire burning your hand and the growing volume of fluid in your bladder is that these both feel like something. It’s probably worth being clear at this point that neither I, nor anyone else, really know if Iggy or his many non-human animal friends have experiences – feelings – more or less like humans do. Much ink has been spilled on this question, much of it back before writing was digital and there was actual ink spilled.^[2]

What we can say, with some confidence, is that people have experiences, sensations, phenomenology, qualia (if you’re a philosopher), consciousness…. whatever you want to call it.

And while a short post is not the right place to explain human consciousness, a good way to think about these sensations is that they measure something in the (internal or external) world and motivate behavior in response to these measurements. [3]

Feeling the pain of the flame really is, in some sense, to be motivated to take appropriate action, removing one’s hand from the fire. As the pain increases – the measurement of heat and the concurrent damage to tissue – the motivation to move one’s hand becomes greater, at some point irresistible.

While it might seem odd to think about human feelings as measurements in the service of motivation and decision making, computer scientists hit on the same solution that evolution did. Consider Watson, a computer designed by IBM engineers to play Jeopardy! For each question, Watson had to decide whether or not to buzz in. To do this, it estimated how likely it is that it had correctly guessed the answer. When this estimate surpassed a predetermined threshold, it “decided” to buzz in. The “feeling of knowing” an answer before being able to produce that answer — What is the capital of New York? — is probably a close analogy to the calculation Watson does.

As the fire/bladder examples show, this idea applies as much to quantities inside the human body as outside it. Different parts of the body keep track of caloric needs, which is experienced as hunger and motivates eating. As needs become greater, sensations become stronger, until eventually they dominate other priorities.

A key point to come out of all of this is that different systems are measuring different quantities, and each measurement will motivate different possible actions, not all of which can be taken at the same time. So, some means is needed to prioritize action. If I am short on calories but faced with, say, an opportunity to make a new friend, I have to decide whether to use my hand to grab a cookie or shake a new hand. Felt experiences help to solve these dilemmas. More pressing needs, because they carry stronger phenomenological experience, push behavior in that direction. (This raises the question of how the mind compares the magnitude of the feeling of hunger with the magnitude of the social opportunity. This is an important, central question for understanding consciousness and I haven’t the first clue about the answer.)

Now, what is being measured is not always as straightforward as one might think. Consider the experience of the urge to breathe, which we all experience when we’re under water or holding our breath. One obvious way this might work is that the body measures how much oxygen is left in the blood and the urge to breathe depends on this measurement.

Except, that isn’t it. If you hook people up to a tube, and, without their knowledge, switch the gas they receive from air to pure nitrogen – so that their oxygen is going down but CO₂ levels are staying relatively constant – their experience isn’t unpleasant at all. (The sense is apparently a bit like getting laughing gas.) In short, the sensory systems that detect CO₂ are measuring the need for oxygen and motivating taking a breath.

This is true of abstractions as well. Our senses of beauty and aesthetics are measuring something. A great deal is now known about what we find beautiful in the human form, and these traits – including the shapes and features of faces and bodies – provide information about age, sex, genetic quality, and so forth.[4] This information, in turn, is useful in the context of selecting others for various sorts of social behavior, including, of course, sex and mating.

Emotions, too, measure and motivate. Fear measures the size and probability of a threat. Pride measures one’s accomplishments. Disgust measures the chance that something will communicate disease. Shame measures the degree to which one’s reputation has suffered because of one’s prior acts. And so on. In each case, the phenomenology motivates a reaction that was (on average) adaptive over evolutionary time, whether escape, avoidance, retaliation, or apology.

Darwin Danger (Created with DALL-E)

The same fear-measuring system that estimated the threat of a charging tiger 10,000 years ago is now trying to figure out whether to be more afraid of driving 70 in a 55 or smoking a cigarette. This issue – the disconnect between the past and present – will be a consistent theme that we explore. Indeed, some practitioners who use Cognitive Behavioral Therapy, though they don’t always put it this way, try to help patients think about how their (evolved) emotions might be producing so-called Cognitive Distortions (in the present environment). So, with a little practice, it’s possible to reduce the chance of a panic attack on a plane (due to a mis-measurement of risks) by reappraising the situation in the context of what we know about flight safety. That new measurement of safety leads to calmness rather than fear. Easier said than done, of course.

We’ll return to this last point in posts to come. (And we’ll ponder some mysteries. Why does popping the bubbles used as packing material feel so satisfying? What makes solving crossword puzzles feel fun?)

For the moment, it might be useful, when you’re experiencing a strong emotion, to ask yourself: what is this emotion measuring, and what is it motivating? Answers to these questions are often tricky and require thinking about how emotions worked in a world very different from the present day.

We’ll pick that up another time.

Citations

Nagel, T. (1974). What is it like to be a bat?. The philosophical review, 83(4), 435-450.

Tooby, J., & Cosmides, L. (2008). The evolutionary psychology of the emotions and their relationship to internal regulatory variables. In M. Lewis, J. M. Haviland-Jones, & L. F. Barrett (Eds.), Handbook of emotions (pp. 114–137). The Guilford Press.

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[1] This is from Catcher in the Rye by JD Salinger. The driver adds, linking the human and non-human world: If you was a fish, Mother Nature'd take care of you, wouldn't she? Right? You don't think them fish just die when it gets to be winter, do ya?

[2] See, among many other sources, Nagel (1974). See also Plato, especially his allegory of the cave.

[3] Yes, we recognize that this bears a resemblance to the view of emotions (Tooby & Cosmides, 2008) as “internal regulatory variables.” Ok. It’s a similar idea but we like the alliteration.

[4] See especially The Mating Mind by Geoffrey Miller.