DARWIN: HUMAN DEVELOPMENT AND BEHAVIOR

 ~ Final Blogpost ~ 

~ Camron Stevens ~ 

~ H2 ~

I talked previously about Charles Darwin’s theory of evolution by natural selection and the discoveries he made while on the Galapagos Islands, but I never really discussed any of his other contributions or concepts. Darwin held his theory of evolution to a high degree, even though it may have opposed the general consensus at the time. However, he was also involved in another issue; an issue that many people have been continuously developing theories and trying to solve for decades. He was interested in gaining more information and contributing to a concept that doctors, scientists, philosophers, and even everyday people crave to understand: human development. In particular, Darwin wanted to figure out where, or what, humans descended from. He devised multiple tests and studies in order to gather specific data and share his findings. Utilizing his observations, Darwin concluded that human beings derived from animal ancestors, which so happened to be another controversial conclusion. Towards the later years of his lifetime, Darwin published a collection of books focusing more on the comparisons between the mental activity of humans and animals. In his 1871 work, The Descent of Man, he further supported his stance on human development and argued that humans’ mental abilities operate similarly to those of animals. 

"The sole object of this work is to consider, firstly, whether man, like every other species, is descended from some pre-existing form; secondly, the manner of his development; and thirdly, the value of the differences between the so-called races of man."    

― Charles Darwin, The Descent of Man

Although others like Thomas Huxley, Charles Lyell, and Alfred Russel Wallace had already addressed the subject of human evolution, the publication of Darwin’s book spurred scientific inquiry into the comparison of the mental sequence between humans and animals. This was partly because the individuals stated above emphasized the mental differences that humans and animals possess, while The Descent of Man highlighted the mental continuity of both. Darwin explicitly indicates that both animals and humans descended from a similar, less developed form, but variability contributed to the evolution and varying attributes of mammals. In addition, he aims to display that there is no inherent difference between humans and animals by concentrating on the mental faculties of them both. In the animals he studied, Darwin detected traces of human-like characteristics in addition to human-like emotions, such as pride, jealousy, and shame. “After examining these and other common mental functions, such as memory, attention, and dreaming, Darwin concluded that the mental difference between humans and the higher animals is one of degree rather than kind.” Ultimately, Darwin claims that the human language and the ability to reason are the conclusive factors that distinguishes humans from animals, accounting for human beings’ more dominant nature. 

“The following proposition seems to me in a high degree probable—namely, that any animal whatever, endowed with well-marked social instincts, the parental and filial affections being here included, would inevitably acquire a moral sense or conscience, as soon as its intellectual powers had become as well, or nearly as well developed, as in man. For, firstly, the social instincts lead an animal to take pleasure in the society of its fellows, to feel a certain amount of sympathy with them, and to perform various services for them.” 

― Charles Darwin, The Descent of Man

The Descent of Man and Selection in Relationship to Sex

Although The Descent of Man received a considerable amount of opposition due to its unprecedented and “anti-religious” contents, Darwin continued his studies and a year later, published another book. The book was titled, The Expression of the Emotions in Man and Animals and it, again, challenged the general ideas and consensus of man. During this time, a large number of scholars viewed spirituality, civilization, and human reason as good evidence of a divine or sacred creation for humans. From Darwin’s perspective, however, the evolutionary record of emotion has evolved throughout history across various cultures and species; therefore, this book argued that each individual human, and some animals, display emotion in parallel and similar manners. Through the process of writing The Expression of the Emotions in Man and Animals, Darwin communicated with multiple scientists and researchers, comparing his findings and details with those of others. One in particular was Guillaume-Benjamin-Amand Duchenne, a French physician who presumed that the faces of humans could demonstrate a minimum of sixty emotions. Additionally, he thought each expression relied on its individual assembly of facial muscles. However, Darwin severely disagreed, believing that facial muscles functioned as one to produce a baseline for only several emotions. Author Jeremy Norman, who took on the task of collecting, evaluating, and studying many of Darwin’s books affirms:

“With this book Darwin founded the study of ethology (animal behavior) and conveyance of information (communication theory) and made a major contribution to psychology. Written as a rebuttal to the idea that the facial muscles of expression in humans were a special endowment, the work contained studies of facial and other types of expression (sounds, erection of hair, etc.) in man and mammals, and their correlation with various emotions such as grief, love, anger, fear and shame. The results of Darwin’s investigations showed that in many cases expression is not learned but innate, and enabled Darwin to formulate three principles governing the expression of emotions—relief of sensation or desire, antithesis, and reflex action” (Darwin Founds Ethology, Studies the Conveyance of Information, and Contributes to Psychology). 

The Expression of Emotion in Man and Animals, by Charles Darwin

In order to test his hypothesis and determine the validity of Duchenne’s theory, Darwin completed what may be the first recorded single-blind (also known as the emotion experiment) study of facial expressions and human emotions. He selected eleven slides produced by Duchenne and ordered them in a random arrangement. He then offered them to his guest one by one, making sure not to give any biased suggestions or innuendos. Ultimately, Darwin speculated that only a select few of Duchenne’s slides were correctly representative of human emotions, and simply asked his guests to choose which slides displayed a certain emotion. Expressions of more general emotions, such as happiness, fear, and sadness generated an almost unanimous decision between the guests. Contrarily, the more unclear and vague slides assembled conflicting and opposing viewpoints.

As the times progressed, however, Darwin’s The Expression of the Emotion in Man and Animals became more and more outdated. A contributing element was his use of Lamarckian concepts throughout the book. The Lamarckian ideas originated from the French biologist, Jean-Baptiste Lamarck, who hypothesized that animals hold the ability to better adapt to their environments through practice and repetition. These adaptations would then be passed down from generation to generation. Originally, Darwin viewed these claims as illogical and unreliable. However, after revisiting several of his own ideas, Darwin began reconsidering the logistics of Lamarck’s theories and incorporating them into his book. One, in particular, was the Associated habits, which suggests that if repeated often enough, an action taken in response to a distinct emotion may become connected through habit, and later evoked by said emotion. This theory was later proven false several years after Darwin’s death, reducing the book’s credibility. Nevertheless, the book still provides credible information and insights into early human development. Though he may have experienced some challenges and opposition for his claims, Darwin’s theories are now universally acknowledged and common beliefs for modern science and research.

Sources Links:

Single-Blind Study - SAGE Research Methods

The expression of the emotions in man and animals

Emotion Experiment | Darwin Correspondence Project

The evolution of emotion: Charles Darwin's little-known psychology experiment

Charles Robert Darwin - Emotional Development, Human, and Theory - JRank Articles

Darwin: From Origin of Species to Descent of Man (Stanford Encyclopedia of Philosophy)

Darwin Founds Ethology, Studies the Conveyance of Information, and Contributes to Psychology 

DISCUSSION QUESTIONS:

1. Does the facial expression of a person always display their true emotion, or do people tend to hide what they are actually feeling?

2. Do you fully agree with Darwin's theory of evolution and human development? What are your thoughts on human development?