What Chimps Can Do: The Cognitive Capacities of Chimpanzees
The list below is taken from the petition filed by the Nonhuman Rights Project for a common law writ of habeas corpus filed on behalf of Kiko (Dec. 13, 2013. Kiko v Carmen Presti; State of N.Y., Supreme Court of the County of Niagara)
Brief writers: Elizabeth Stein and Steven Wise
The most important cognitive ability is "autonomy," which the other cognitive abilities support. These include, but are not limited to, the possession of an autobiographical self, episodic memory, self-determination, self-consciousness, self-knowing, self-agency, referential and intentional communication, language planning, mental time-travel, numerosity, sequential learning, meditational learning, mental state modeling, visual perspective-taking, understanding the experiences of others, intentional action, planning, imagination, empathy, metacognition, working memory, decision-making, imitation, deferred imitation, emulation, innovation, material, social, and symbolic culture, cross-modal perception, tool-use, tool-making, cause-and-effect.
1. Like humans, chimpanzees have a concept of their personal past and future and suffer the pain of not being able to fulfill their needs or move around as they wish; like humans they experience the pain of anticipating never-ending confinement. Similarly, because chimpanzees have a self-concept, are aware of their past and see a future before them, they can re-experience past pains and pleasures, as well as anticipate them. This implies that, like humans, they can experience pain over an event that has yet to occur.
2. Humans and chimpanzees share those brain circuits involved in such complex cognitive abilities related to autonomy such as communication, language, insight, fore-planning, decision-making, the processing of complex social information, emotional learning, and awareness, as well as highly specific cell types involved in such higher-order thinking and brain functions.
3. Both human and chimpanzee brains are similar in terms of how their brains develop and mature, indicating that chimpanzees and humans pass through similar cognitive developmental stages, including the development of communication; both possess the brain asymmetry related to language capacities.
4. Both humans and chimpanzees exhibit developmental delay, a protracted period of brain development that plays a role in the emergence of such complex cognitive abilities as self-awareness, creativity, fore-planning, working memory, and decision making.
5. The autonomous behavior of chimpanzees reflects their ability to choose, and is not based on reflexes, innate behaviors or on any conventional categories of learning such as conditioning, discrimination learning, or concept formation.
6. Chimpanzees possess a sense of self that developmentally emerges in a manner similar to humans and is highly stable over time. They recognize themselves in mirrors and on television and can use a flashlight to examine the interiors of their own throats in a mirror. Adult chimpanzees recognize photographs of themselves as youngsters. The concept of self is an integral part of having goals and desires, intentionally acting to achieve those goals, and knowing whether they have succeeded. This sense of self is an integral part of self-determination and autonomous behavior.
7. A critical demonstration of autonomy is that chimpanzees, like humans, not only understand they exist through time, they engage in "mental time travel," which is the ability to recollect the past and plan for the future. "Mental time travel" is enabled through the "episodic system," by remembering events and anticipating the future. So-called "autonoetic consciousness," or "self-knowing consciousness," is a necessary correlate of their possessing an episodic system. It is autonoetic consciousness that gives us our autobiographical sense of self.
8. "Numerosity," which is the ability to understand numbers as a sequence of quantities, requires not only sophisticated working memory (in order to keep numbers in mind), but a conceptual understanding of a sequence, which is closely related to "mental time travel?' and planning out the right sequence of steps towards a goal, two critical components of autonomy. Chimpanzees excel at understanding sequences of numbers and understand that Arabic symbols ("2", "5", etc.) represent discrete quantities.
9. Chimpanzees demonstrate "episodic memory". They remember the "what, where and when" of events that occurred years ago, and can plan to act when they are in a different psychological state from the one in which they are when they plan.
10. Chimpanzees can delay a strong desire for a better future reward, generalize a novel tool for future use, select objects for a much-delayed future task, and do all of this while keeping in mind several elements of a situation. Part of being an autonomous individual is self-control. Chimpanzees, like humans, can delay gratification for a future reward; they possess a high level of self-control under many circumstances. Chimpanzees can select a tool they have never seen, guess its function, and use it later. This would be impossible without mentally representing the details of the future event. Chimpanzees plan for future exchanges with humans.
11. Chimpanzees demonstrate "self-agency," the ability to distinguish actions and effects caused by oneself from events occurring in the external environment. Self-agency is a fundamental component of autonomy and purposeful behavior. These and many similar findings demonstrate that chimpanzees and humans share the fundamental cognitive processes.
12. Chimpanzees, like humans, possess material, social, and symbolic culture. Culture is behavior learned by watching others, represents something most individuals do, and is characteristic of a group or community. Culture is based on several high-level cognitive capacities, including imitation (the direct mimicking of bodily actions), emulation (learning about the results of someone else's actions, then achieving those results in another way) and innovation (producing novel ways to do things and combining known elements in new ways) all of which chimpanzees share with humans. All three types of culture presuppose a common set of mental abilities, the most important of which are imitation (which is an important hallmark of self-awareness) and emulation, both of which require the ability to learn by observation. Symbolic culture involves the use of arbitrary abstract symbolic gestures in the wild and language in some captive chimpanzees.
13. When imitated, both chimpanzees and young children tend to "test out" the behavior of the imitator by making repetitive actions and looking to see if the imitator does the same. This "contingency-checking" is similar to how a chimpanzee and toddler test whether an image in a mirror is herself, and is another hallmark of-self-awareness. Chimpanzees are capable of "deferred imitation," copying actions they have seen in the extended past, which relies upon even more sophisticated capacities than direct imitation because the chimpanzees must remember the past action of another while replicating those actions in real time.
14. Not only do chimpanzees understand they have minds and reflect upon their own thoughts and. states of knowledge, they may understand that others have minds, and those other minds know things they don't. That is, they demonstrate "theory of mind." They imitate the actions of others and anticipate others' intentions when watching a human or another chimpanzee try to complete a task. They know what others can and cannot see, and understand the visual perspective of another chimpanzee. They know when another's behavior is accidental or intentional. They use their knowledge of others' perceptions to deceive other chimpanzees and obtain hidden food or to hide themselves from other chimpanzees and humans. In situations where two chimpanzees compete for hidden food they use strategies and counter-strategies to throw each other "off the trail" and obtain the food for themselves. Both language-trained and wild chimpanzees adjust their gestures and gestural sequences to the attention state of the individual they are trying to communicate with, using visual gestures towards an attentive partner and tactile and auditory gestures more often toward inattentive partners. If the partner does not respond, they repeat the gesture. This complexity in understanding others' minds is evidence that they are aware of their own mind and the minds of others. They have a capacity for empathy in that they can identify with and understand another's situation, feelings, and motives.
15. Chimpanzees use their imaginations to engage in pretend play.
16. Language in humans and chimpanzees is a volitional process that involves creating intentional sounds for the purpose of communication; it is a reflection of autonomous thinking and behavior. Chimpanzees exhibit referential and intentional communication. Their development of their use and understanding of sign language, along with their natural communicative gestures and vocalizations, parallels the development of language in children. This points to deep similarities in the cognitive processes that underlie communication in chimpanzees and humans. Both children and chimpanzees trained in the use of American Sign Language (ASL) and other symbolic methods of communication use their symbols to comment on other individuals and about past and future events. They can purposefully create declarative sentences. They discuss social situations with humans, such as where they want to go, who they want to be with, what they intend to do, what they want to eat, and how they feel; chimpanzees communicate what other chimpanzees want. They can state what they intend to do, in advance of acting, then carry out their stated actions, sometimes coordinating their actions, which requires them to form a thought and hold it in mind at least until agreement is reached. They point and vocalize when they want humans and other chimpanzees to notice something and will adjust their gesturing to insure they are noticed. In tasks requiring cooperation, chimpanzees recruit partners they know to be the most skilled and take appropriate turns when requesting and giving help to a partner. They communicate intentionally and purposefully when they want to inform naive chimpanzees about something, such as a predator. Chimpanzee communication is also based on conversational interaction in which each participant exchanges turns communicating in a give-and-take manner and participants respond appropriately to the communicative actions of each other. Chimpanzees understand that conversation involves turn-taking and mutual attention. If they wish to communicate with a human whose back is turned they will make attention-getting sounds. If the human is turned to them, they switch to conversational sign language with few sounds.
17. Chimpanzees demonstrate that they can learn abstract symbols for hundreds of items, events, and locations, without being taught, solely through observation, which they intentionally use in practical situations, remember for decades, and master a syntax.
18. When humans feel a conversation has broken down, they repeat their utterance and add information to the original utterance. Signing chimpanzees conversing with humans respond the same way, reiterating, adjusting, and shifting the signs they make to create conversationally appropriate rejoinders; their reactions to and interactions with a conversational partner resemble patterns of contingency in conversation, which is a key demonstration of volitional and purposeful communication and thought. ASL-using chimpanzees demonstrate contingent communication with humans at the same level as young children. Similarly, chimpanzees who have learned other forms of symbolic communication monitor the listener and make judgments about what he is understanding in order to proceed with the conversation.
19. Both chimpanzees trained and untrained to engage in signed conversation string together multiple gestures to create gesture sequences. They may combine gestures, into long series, within which gestures overlap, be interspersed with bouts of response waiting, or be exchanged back and forth between individuals. Both ASL-trained and wild chimpanzees adjust their gestures and gestural sequences to the attention state of the individual they are trying to communicate with, using visual gestures towards an attentive partner and tactile and auditory gestures more often toward inattentive partners. If the partner does not respond, they repeat the gesture.
20. In a manner similar to children ages two through seven, sign language-trained chimpanzees exhibit a volitional use of language by engaging in "private speech," that is, signing to themselves. Private speech is part of the normal development of communication, self-guidance, self-regulation of behavior, planning, pacing, and monitoring skills and helps control and regulate their emotions and thoughts by focusing them on their own concerns and providing a buffer from external distractions. It is also related to more creative and imaginative play.
21. "Sequential learning" is the ability to encode and represent the order of discrete items occurring in a sequence. It is critical for speech and language processing, the learning of action sequences, or any task that requires putting items into an ordered sequence. Chimpanzees can count or sum up arrays of real objects or Arabic numerals and display the concepts of ordinality and transitivity (the logic that if A — B and B C, then A = C) when engaged in numerical tasks, which demonstrates a real understanding of the ordinal nature of numbers. They understand proportions (e.g., 1/2, 3/4, etc.). They can learn to name (using a symbol-based computer keyboard) the number, color and type of an object shown on the screen. They can use a computer touch screen to count from 0 to 9 in sequence.
22. They have an understanding of the concept of zero and use it appropriately in ordinal context. They display "indicating acts" (pointing, touching, rearranging) similar to what human children display when counting up a sum. Just as human children touch each item when counting an array of items, chimpanzees do the same thing, demonstrating similarity in the way numbers and sequences are conceptualized.
23. Not only do chimpanzees understand numbers and sequences, but their working memory of numbers, that is, their short-term memory and ability to keep several items in mind at the same time, and temporarily store, manipulate and recall numbers, objects, names, etc. compares to that of adult humans. The chimpanzees' extraordinary working memory capability underlies such mental skills as mental representation, attention, and sequencing.
24. Chimpanzee social life is cooperative and collaborative. Chimpanzees ostracize chimpanzees who violate social norms. They appear to have moral inclinations, and a level of moral agency that reflects moral imperatives and self-consciousness.
25. Chimpanzees demonstrate an awareness of death, which is one of the consequences of self-awareness, as well as compassion, bereavement-induced depression, and an understanding of the distinction between living and non-hiving, in a manner similar to humans. Chimpanzees, like humans, feel grief and compassion when dealing with mortality.
26. Chimpanzees exhibit other capacities •that stem from self-awareness. These include "metacognition." This is the ability to reflect upon one's own thoughts and to understand what one does and does not know. Chimpanzees possess a capacity for tool-making. This implies complex problem-solving skills and an understanding of means-ends relations and causation. It requires making choices, often in a specific sequence towards a predefined goal, which is a key aspect of intentional action (chimpanzees generally demonstrate an ability to infer causation). Chimpanzees make and use compound tools that require them to utilize two or more objects towards a single goal, use "tool sets," which requires them to use two or more tools in an obligate sequence to achieve a single goal, and "tool kits," which is a unique set of about 20 different tools chimpanzees use for various functions in their daily lives.
27. Chimpanzees are quite competent at "cross-modal perception." They can take in information in one modality such as vision or hearing, then internally translate that information into another modality. They can also take in symbolically encoded information and translate it into any non-symbolic mode. When shown a picture of an object, they can retrieve that object by touch alone. They can retrieve the correct object by touch when shown only the symbol representing that object. They can match faces, even photographs of faces, to voices, even recordings of voices
28. Chimpanzees engage in "mediational learning." They are able to "figure out" rules that allow them to solve new problems based on past information which they collate over multiple trials and reflect upon. This requires an ability to compute relationships among a variety of things and events. They understand they are positing predictive or cause-and-effect relationships about tasks they work on and that they have control over what they do and what will happen.