The Science of Emotions & Relationships

The episode opens with Andrew Huberman introducing himself as a professor of neurobiology and ophthalmology at Stanford School of Medicine. He says the podcast is separate from his teaching and research roles there and is part of an effort to bring zero-cost-to-consumer science information to the general public. He places the episode in a month devoted to the science of emotions, following earlier discussions of stress, resiliency tools for reaching calm and raising one's stress threshold, and motivation and the dopamine system.

Two resource announcements come before the main topic. First, all Huberman Lab episodes now have expert-made captions in English and Spanish on YouTube. The host says there may be the occasional error but that the captions are, for the most part, very precise, and that more languages will be added. Second, he points to a free, roughly 30-minute non-sleep deep rest (NSDR) script produced by Madefor, a previous sponsor. He describes NSDR as a way to reach calm quickly and in a self-directed way, whether to fall asleep more readily, to de-stress deeply or to replace lost sleep. He adds that it also seems to aid neuroplasticity and says there is scientific support for that. This script leaves out the intentions and more typical language of yoga nidra and focuses on breathing protocols and a body scan.

The core claim of the introduction is that emotions make up most of what we think of as our experience of life: behaviors, places and encounters all funnel into our emotional perception of what those things meant. The host also stresses that everyone's perception of emotion is slightly different. He supports this with an analogy from color vision. The red-sensing cells in two people's eyes can be identical down to the genes they express, yet psychophysical studies show that two people asked to pick the most intense of 10 reds will choose very differently. He presents this as a counterintuitive result, since something as simple as color might be expected to be universal.

We need to agree at the outset that emotions are complicated and yet they are tractable. They can be understood.

The stated goal is practical. The host wants to give listeners ways to understand what their emotional states mean and do not mean, so they can judge whether to hold a given emotional state as true, whether it carries meaning, and whether other people's emotions matter to them in a given context. He also states his limits plainly: he is not a clinical psychologist or a therapist, although he has some background in psychology. He says he will draw on the major figures who studied emotion and emotional development and link their work to the neuroscience of emotion. He grants that no single, universally true theory of emotion exists, but argues that some ground truths emerge where the existing theories overlap.

The planned discussion centers on development, especially infancy and puberty, and on tools for widening emotional range and handling difficult emotional situations. The host also previews some "absolutely wild and wacky experiments" in which people inhale different hormones to try to form attachments more quickly, and says he does not necessarily recommend them. He describes the episode as more interactive than previous ones, with exercises listeners can do in real time.

Before turning to emotion itself, the host sets out a methodological rule from neuroanatomy. Brains differ considerably across 50 individual humans, and even more between dogs and humans. To understand what a brain area does, he says, you must answer two questions. The first is what the area connects to: where its inputs come from and where it sends outputs. His example is an area that receives direct input from neurons in the nose, which likely has a role in analyzing odors, and that, if it also receives input from the eye, cares about light as well. The second is the structure's developmental origin. The brain is a "squishy thing" floating in liquid inside the skull, so structures move around during development and may sit in different places in different species or individuals. Where a structure started out informs what it does.

Applied to emotion, the host argues that no one brain area is responsible. He acknowledges the so-called limbic system, which has been linked to emotions in various ways, but calls it just one of the inputs that create emotions, not "the place for emotions." A lesion in one brain location will not eliminate emotions entirely.

He then lays out a live scientific disagreement. For years, researchers thought there might be dedicated circuits that generate the feeling of being happy, others for being sad, and so on. Lisa Feldman Barrett has challenged this head-on, and the host says she has very good evidence that such circuits probably do not exist. His own view is that there is good evidence for limbic and other circuits that shift overall states instead: levels of alertness or calmness, and whether attention is biased toward the outside world or toward what is going on inside the body. So he rejects dedicated circuits for specific feelings while still holding that emotions arise from specific connections between specific areas in the brain and body.

That leads to the developmental focus. If we want to understand how emotions work, the host says, we have to look at how they are built. That building happens during infancy, adolescence and puberty and continues into adulthood, but the groundwork is laid early, in small children.

The developmental account rests on two modes of attention that the host says operate, to some degree, at the same time throughout life. Interoception is attention to what is happening inside you, what you feel internally. Exteroception is attention to what is happening outside. He calls the fact that people both interocept and exterocept all their lives "absolutely critical" to understanding emotions.

A newborn, in this account, has no knowledge of what it needs. It does not understand hunger, toys, cold or heat. When it needs something, it experiences that need as anxiety, or a rise in alertness, for example when hungry or needing to use the bathroom. It responds by vocalizing, crying, cooing or acting agitated. A caregiver then decides what is needed, such as milk, a diaper change or a blanket. The host notes that caregivers cannot actually know whether the baby is cold. They can only assume it.

From this the host draws a central point: babies have no sense of the outside world except that it responds to their expressions of anxiety. He separates this from Freudian theory, while acknowledging that parts of it are embedded there, and says that all developmental psychologists agree babies lack the ability to make cognitive sense of the outside world. Through the loop of registering an internal state, crying out and being answered, infants begin to form a relationship with the outside world in which shifts in their internal states drive requests that people come and respond to, "hopefully."

The "hopefully" refers to neglect. The host acknowledges that development goes badly when babies, adolescents or teenagers are neglected, but calls those cases extreme. He compares them to laboratory studies of "enriched environments," where mice given toys, varied foods and companions are reported to have thicker brains and neurons with more branches. His caveat is that such studies are "really comparing deprivation with normalcy." He says he finds healthy emotional development more interesting, along with the question of what interventions later in life might rescue development that did not go well.

Here the host gives his working definition: emotions are really about forming bonds and being able to predict things in the world. He is careful about the limits of what can be known. Whether a baby feels angry, happy or sad, we can guess but do not know. He extends this to adults: most of the time we do not even know how we ourselves feel, let alone how others feel. Unless someone reports an extreme state, such as being very depressed or very happy, a listener cannot really know their feelings from a description. He adds that listeners have no idea whether he is furious or very happy at that moment. Expressions and cues such as pupil dilation exist and will be discussed, but he maintains that "you really don't know."