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Book Review: The Interbrain

British psychoanalyst Adam Phillips often referred to nonverbal communication as “what falls out of the patient’s pockets while he’s speaking.”

For Digby Tantam, a psychiatrist, professor, and author of The Interbrain: Embodied Knowledge Connections Versus Common Knowledge, what is emitted, rather than spoken, forms a shared language that connects us all. This language offers many clues to our understanding of human nature, morality, psychopathy, and even terrorism.

Tantam begins by exploring the subject of intuition.

“Intuition for many non-scientists means almost the opposite of what scientists do. It means knowing things by some other route than demonstrating them,” writes Tantam.

Mirroring, or the expressed congruent facial expressions such as smiling when someone smiles or copying another person’s gestures is just one example. Yet implicit connections between living beings happen much more than we know.

“The tail flick of one deer causes the gluteal muscles of other deer nearby to stiffen, ready for a leap and then a run. We could make a kind of case for saying that the deer who was the source of the signal was controlling the brains of the other deer inasmuch as the sources of the deer’s signal caused the gluteal contractions of the other deer. We could even say – if we were not so sure the physical separation of two bodies was the major criterion for each having a separate identity – that the source deer had for a short time usurped the action controller in the brain of each of the other stiffening deer and had for a short while taken over the other deer’s brain,” writes Tantam.

Unlike mental connections that start from the point of view of the individual discovering connections in the world, interbrain connections start with the experience of sharing. Individual experiences are realized later.

One way we can understand interbrain connections is through the study of crowds, which Tantam says share three main characteristics: the disappearance of conscious personality; the turning of feeling and thoughts in a definite direction; and being brought together – all of which are enhanced by nonverbal communication.

“As nonverbal communication is enhanced by similarity, more homogenous crowds are more immersive. Nonverbal communication also gains weight when there is reduplication of the same expressions or movements in different bodies,” writes Tantam.

The feeling of threat also increases interbrain connectedness and, particularly when oxytocin is present, it enhances already existing connections and attachment. This explains the behavior of what we know as swarms and mobs.

However, interbrain connections don’t completely usurp our behavior. Instead they add dimension to it.

“I consider that the interbrain connection has a much stronger influence over individual behavior than do the advocates of intersubjectivity, so much so that two states of human functioning can be discerned: Homo individualis and Homo socialis. These two modes of function can alternate, can blend, or can be in conflict,” writes Tantam.

Some emotions, like shame and pride, depend on judgements of social status. We feel inferior or marginalized when we feel shame, and conversely, we feel superior when we feel pride. However, it is the existence of the interbrain connections with other individuals or groups that make it possible for group members to put their own self-motivated interests aside to act on behalf of the group.

“The interbrain is one explanation for altruism or, to use another metaphor, self-sacrifice. Preserving the life of a child at one’s own expense is an example of altruism that people might acknowledge as credible even if they otherwise thought that life was about ‘looking after number one,’” writes Tantam.

Conversely, interbrain connections can also be formed through negative emotions, such as disgust, hate, hostility, and contempt.

“Demonization of offenders increases the public’s desire to punish them retributively. This is most likely because of common knowledge, which seems to be widespread, that demons exist, that they are evil, and that evil is contagious,” writes Tantam.

Our fascination with demons, psychopaths, and examples of immorality might also be a way to measure our own ability to connect to other people against the monster’s disconnection from us all.

“People do act in terribly evil and inspiringly good ways. What makes this such a concern for all of us is that we want to increase good and reduce evil – although we cannot agree on how to do it, or sometimes even what good and evil are – but I have argued that human beings are truly social animals, connected not only in spirit through a culturally acquired shared or common knowledge about people but also via an innate connection provided by our brains, via specialized structures and networks that mediate nonverbal communication,” writes Tantam.

Exploring compelling science, informative historical examples, and modern day phenomena, Tantam provides a unique look at human nature; what connects us, what divides us, and what we can learn from knowing the difference.

The Interbrain: Embodied Knowledge Connections Versus Common Knowledge

Digby Tantam

Jessica Kingsley Publishers

January 2018

Softcover, 309 Pages

Book Review: The Interbrain

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Claire Nana

Claire Nana is a regular contributor and book reviewer for Psych Central.

APA Reference
Nana, C. (2018). Book Review: The Interbrain. Psych Central. Retrieved on October 30, 2020, from
Scientifically Reviewed
Last updated: 11 Mar 2018
Last reviewed: By a member of our scientific advisory board on 11 Mar 2018
Published on Psych All rights reserved.