How Does Culture Influence the Way We Use Our Brains? Find Out Here.

We’ve all heard of “right-brain” and “left-brain” thinkers.

Left-brain thinkers are thought to be more logical and mathematical, while right-brain thinkers tend to lean emotional and artistic.

But are there any links between the way our brains function and our cultures?

We’ve talked a lot about gene-culture coevolution over these past few weeks.

In short, the theory suggests that genetics and culture are interconnected.

This brain imaging study about visual perceptual tasks seems to substantiate that theory.

Individualist vs. Collective 

Psychological research has shown that individualist and collective values are demonstrated in an individual’s view of objects in relation to their context.

Americans, valuing individuality, tend to view the two as independent from each other.

East Asian cultures, which value the collective, view objects as contextually interdependent.

These differences have been shown to impact perception and memory by behavioral scientists.

The Study: How Our Brains Work

A study by the Massachusetts Institute of Technology took a look at whether these cultural tendencies can be measured in brain activity patterns.

Using functional magnetic resonance imaging (fMRI) scans from a group of 20 participants – 10 from East Asia, 10 from the U.S. – McGovern Institute for Brain Research Professor John Gabrieli and his team examined participants’ mental operations.

Participants were asked to compare a sequence of images, and their mental operations were mapped via blood flow changes in the brain.

The images were lines within squares.

Participants were asked to compare each image with the previous image, making judgments based on relative judgments of interdependent objects or absolute judgments of individual objects without context.

For instance, some questions asked whether the lines were proportional to the squares, regardless of size (interdependent); others asked whether the lines were the same length as each other, regardless of the squares (independent of context).

The Results: Confirmed

While the simplicity of the task resulted in no differences in accuracy between the groups, brain activation patterns did differ.

Relative judgments, which have been shown to be harder for Americans, stimulated the brain regions dedicated to mental tasks that demand attention. 

These regions were less active for absolute judgments.

As you might guess, the results for the East Asian group were the opposite, with brain activity becoming more active for absolute judgments and less for relative.

The paper’s lead author, Trey Hedden, said of the study:

“We were surprised at the magnitude of the difference between the two cultural groups, and also at how widespread the engagement of the brain’s attention system became when making judgments outside the cultural comfort zone.”

Even more interesting, questionnaires had been distributed prior to the exam to see how closely each individual identified with their culture, using questions regarding values and norms.

Those individuals who identified more intimately with their culture’s values showed a stronger reactive pattern of brain activity relative to their culture.

This study suggests that our culture – and how closely we individually identify with our culture – can influence the way our minds work.

Pretty heady.

Are Facial Expressions Perceived Differently Across Cultures? Find Out Here.

Languages have shaped our genetics in terms of physiological differences in speech.

The roof of the mouth, for instance, differs across cultures.

But language isn’t the only part of communication.

Facial expressions and mannerisms are a big part of communication, and the interpretation of these types of expression differs across cultures.

The facial musculature of humans is highly developed, far more so than in any other primate species.

As such, the lips and eyes reveal a lot about human emotion.

According to Herbert Gintis’ “Gene-culture coevolution and the nature of human sociality”:

“Humans have evolved a highly specialized and very costly complex of physiological characteristics that both presuppose and facilitate sophisticated aural and visual communication, whereas communication in other primates, lacking as they are in cumulative culture, goes little beyond simple calling and gesturing capacities.”

While other primate species’ may go “little beyond,” how far does ours go?

Emotional Expression

Prior studies have suggested that the evolutionary nature of facial expressions does not differ across cultures, but at least one study has found that expressions of happiness, anger, and sadness are perceived differently between the East and the West.

According to the study’s abstract:

“Briefly stated, the universality hypothesis claims that all humans communicate six basic internal emotional states (happy, surprise, fear, disgust, anger, and sad) using the same facial movements by virtue of their biological and evolutionary origins [Susskind JM, et al. (2008) Nat Neurosci 11:843–850].”

Published by the American Psychological Association in the Journal of Experimental Psychology: General, the research, led by Rachael E. Jack, PhD, of the University of Glasgow, opposes this theory.

The Study

Looking at the way in which Western Caucasians and East Asians view various expressions according to their facial features, two groups – one of Caucasians and one of Chinese participants – were selected.

The study’s participants viewed emotion-neutral faces that were altered at random using technology. They were asked to classify the faces as happy, sad, angry, disgusted, fearful, or surprised.

Researchers were then able to identify the facial features that the groups of participants associated with the emotions.

From the responses, researchers deduced that Western Caucasians focused more on the mouth and eyebrows when identifying facial expressions, while Chinese participants focused primarily on the eyes.

These differences can lead to complexities in communication across cultures, resulting in misinterpretation or missed signals of emotional expression. 

The findings support the concept of gene-culture coevolution and how culture is increasingly driving human behavior more than genetics.

We’ll talk more about cultural mannerisms and body language next week.

From Mandarin to Italian, How Language Shapes Genetics

Can you differentiate Mandarin from French or Italian?

Of course, you can. 

The sounds of each of these languages are very different, from hard or soft consonants to long or short vowels.

Due to the dynamic sounds of each mother tongue, you can see the adaptation of different vocal tracts across cultures.

These adaptations have developed across generations according to the languages spoken in countries around the world.

We discussed gene-culture coevolution last week in relation to the human species and speech.

Now, let’s talk about how speech and language have evolved our genetics across cultures.

Physiological Traits Adapt to Language

Speech-related physiological adaptations vary across the human species according to the language spoken.

Some languages, like German or Arabic, require deep guttural sounds due to the harsh consonants.

Others, like Spanish, require speakers to roll their r’s.

One of the ways in which this presents in our physiology was reported by Discover Magazine.

Researchers found that the roof of the mouth differs across cultures, according to how vowel sounds are pronounced. 

Furthermore, these anatomical variations evolve upon each generation, creating an evolution in the language itself and the sounds of speech.

The study’s author, Linguistics Expert Dan Dediu, says, 

“Even small variations in the shape of our vocal tract may affect the way we speak, and this may even be amplified — across generations — to the level of differences between dialects and languages.”

The Study

How did researchers discern this change?

The study looked at over 100 people from several ethnolinguistic groups in Europe, North America, China, and across India.

MRI scans were taken of the hard palate of each participant.

Using the scans and machine learning, computer models formed a picture into the future of the hard palate and the sounds it might produce. 

Five commonly used vowel sounds – the “uh” in sofa,” the “ah” in “hot,” the “oo” in “boot,” the “a” in “bat,” and the long “e” in “feet” – were plugged into the computer model. 

A second generation, mimicking the sounds from the first, showed the amplified pronunciation of each sound – as did 50 generational models after it.

Though the change in the shape of the hard palate over time only impacted pronunciation slightly each generation, the change in the vowel sounds after 50 generations was much more pronounced.

The researchers write that,

“besides culture and environment, quantitative biological variation can be amplified, also influencing language.”

This research begs the question: what will our languages sound like in 50 generations…and how did they sound 50 generations ago?

The Myth of Spanish King Ferdinand, the Lisping King & the True Gene-Culture Coevolution of Speech

There is a common myth in Spain that King Ferdinand was born with a lisp.

As the story goes, this speech impediment led to the Spanish pronunciation of “z” and “c” with the soft “th” sound, as Ferdinand’s courtiers imitated his lisp.

This Spanish pronunciation of “z” as “th” differs from the “z” as “s” spoken in western Spanish-speaking countries.

In reality, the “s” sound exists in the Spanish language; it is just not applied to “z” or “c” (the latter, when followed by “i” or “e”). 

Thus, it follows that the differences in pronunciation across Spanish-speaking cultures are not due to a lisping king, but rather to the natural regional differences that develop in living languages.

In the same way that American pronunciation of English varies from British pronunciation, peculiarities of living languages emerge across many groups, regions, countries, etc.

While King Ferdinand’s story is nothing but an urban legend, culture and genetics really do work together to create physiological differences related to speech.

Here’s how.

Genes & Culture Interact

Herbert Gintis’ paper titled, “Gene–culture coevolution and the nature of human sociality,” defines the gene-culture coevolution theory as follows:

“Gene–culture coevolution is the application of sociobiology, the general theory of the social organization of biological species, to humans—a species that transmits culture in a manner that leads to quantitative growth across generations.”

Cultural differences have produced changes in brain size, body size, and other aspects of human anatomy across the human species.

Last week, we talked about how genes and culture worked together to alter our diet – specifically, our ability to consume milk products – and how that ability varies across cultures according to their cultural history.

In the same way, gene-culture coevolution has symbiotically shaped human speech and communication.

Speech & Communication

Gintis goes on to explain how gene-culture coevolution is readily apparent in the physiological evolution of human speech and facial communication.

He writes that genetic alterations that improve speech are propagated due to the increasing importance human society places on communication. 

In early humans, speech production was facilitated by the evolution of regions in the motor cortex, including the adaptation of muscles and nerves in the tongue, larynx, and mouth that help produce speech.

Other physical attributes that have adapted over time in humans to improve speech include a low larynx in the throat, a shorter oral cavity, and the hypoglossal canal of the tongue, all of which both help produce sounds.

The Wernicke’s and Broca’s regions in the cerebral cortex are either absent or are very small in other primates; they’re large in humans, enabling comprehension and speech.

Human facial musculature is also more highly developed, allowing the eyes and lips to impart nonverbal communication.

Considering the development of these attributes that facilitate speech in humans, you can see that genes and culture have worked closely together to evolve the human species.

Next week, we’ll talk about how these physiological aspects of speech differ across cultures.