Pierre Boulle is a name unknown to most. His limited contributions to literature and cinema, however, are transcendent. Boulle authored Bridge on the River Kwai and Planet of the Apes in 1952 and 1963, respectively, both of which were adopted into the namesake award-winning films. They are among my favorite films because of their fascinating examinations of human behavior. In another piece, we’ll discuss the dynamics of the River Kwai. The apes will be at center stage this week.
Does the Chimpanzee Have Theory of Mind?
Fifteen years after Boulle authored Planet of the Apes, psychologists David Premack and Guy Woodruff published a provocative paper titled “Does the Chimpanzee Have a Theory of Mind?” Around this same time, Jane Goodall was observing the first instance of chimpanzee warfare. No, that’s not a typo. From 1974 to 1978, the Gombe Civil War took place amongst warring chimpanzee tribes in Gombe National Park in Tanzania. Her observations of cannibalism, revenge, and violence shook the scientific community who until then thought of chimpanzees as nothing more that semi-aggressive banana mongers. Her observations demonstrated a terrifying sophistication connecting their behavior to ours.
Though their work was not connected, the timing of Premack and Woodruff’s paper and the conclusion of the Gombe Civil War is peculiar. Also, what is theory of mind? And why was discovering it in chimpanzees shocking?
What is Theory of Mind?
Theory of mind is a psychological concept concerning the capability of humans to understand mental states of other humans. Its advancement is central to our overall cognitive development, especially as children. There is no universal definition of these developmental stages, but there are well-defined indications of its progress:
- Comprehension of desire in others – ages 1-2
- Comprehension of difference in thought – ages 2-4
- Identification of knowledge differences and prediction of thought in others – ages 4-8
- Leveraging discrepancies in knowledge – ages 8-12
- Interpretation and inference of social cues and empathy – ages 12+
The conclusion of Premack and Woodruff’s paper suggested chimpanzees possess the capacity to predict behavior, but are unable to leverage knowledge discrepancies. The most concrete example of leveraging knowledge discrepancies is the Sally and Anne experiment designed to demonstrate false beliefs, the notion another entity does not possess the same knowledge as you, and therefore will have, as the name suggests, false beliefs.
A Less Developed Theory of Mind
The Sally and Anne experiment begins with Sally hiding a marble in a basket. Sally then leaves the room. Anne, who is in the room with Sally, has a box. While Sally is away, Anne moves the marble from Sally’s basket to her box. Anne then leaves the room and Sally returns. Anne is then asked where she expects Sally to look for the marble. If Anne has an understanding of false beliefs, she would postulate Sally would look in the box first because that’s where she left the marble.
Premack and Woodruff conducted a similar experiment with chimpanzees, the only difference the two chimpanzees possessed disproportionate knowledge regarding the location of food. The chimpanzees were inconsistent in predicting where the other would look for the food, suggesting they didn’t comprehend the other’s false belief.
Language Development and Human Theory of Mind
One major factor in advancement of human theory of mind is language development. Practically speaking, the higher our language development, the more mental states we can ascribe and better enable abstraction and socialization. Language development in many cases is also an indicator of knowledge discrepancies, an indicator that’s enforced by human societies through areas such as education.
Chimpanzees and other primate societies do not possess the same language development, although they do possess a dialect which enables group communication. Luckily, or unfortunately, Pierre has already asked and answered the next provocative question – what if chimpanzees had a language as sophisticated as ours?
Our Unique Human Capabilities
The genesis of this piece stems from a fascinating YouTube channel called Real Science. Rather obviously, they did a piece on chimpanzees, which exposed me to Goodall’s research and the Gombe Civil War, which fascinated me enough to write my own piece about theory of mind, which lead me to Premack and Woodruff as well as Jean Piaget, the godfather of child developmental psychology. This process and the human mind which enables it continue to fascinate me.
Our ability to string together seemingly unrelated ideas, to theorize about metaphysical concepts, and to develop hyper advanced technology to augment our advancement beyond any other species in existence cannot be underestimated. Sitting in the shadows in Africa, or through the glass at a zoo, there is a species thinking in a lesser but familiar pattern and engaging in terrifying activities, the consequences of which we know all too well. That species is one mutation away from being able to evolve into us. Don’t fear, but don’t take your human capabilities for granted.
Be More.
Become Polymathic.
Quote of the Week: “The greatest danger to our future is apathy.” – Jane Goodall