The human brain has been studied in microscopic detail and shown neural structures among nerve cells, that have not been found in any other animal. This challenges the suggestion that the human brain is an enlarged version of a chimpanzee brain. Alternatively, cognitive studies have found animals to have certain abilities that were thought to be unique to humans. This ‘intelligence’, caused debate which has developed over time. Intelligence does not have one exact definition so to say, but has been mentioned as “enabling animals to behave adaptively” (Pearce 2008).
Anthropomorphism is the presence of human characteristic or behaviour in animals. It suggests that humans and non-human animals have similarities. Thorndike (1911), studied the automatic reactions to direction and space in chicks. They were placed at the top of a box and left to decide whether they will jump down or not. Research showed that if the distance was less than 10 inches, the chicks would jump with no hesitation. At 16 inches, they jumped within 5 to 240 seconds. After 22 inches they jumped but with some restraint, and lastly, at 39 inches the chicks did not jump at all. Thorndike himself stated that no insinuations were made to say there is the same awareness of space perception in chicks, similar to humans, but you can suggest that the experiment is interpreted in an anthropomorphic way. This study suggests that chicks have a similar spatial perception to humans and that they are also capable of assessing danger in a situation, which is shown by the hesitation to jump at larger heights. This also suggests the intelligence comparable to humans.
Another example of this is a study conducted by Frans de Waal (2003) called the fairness study. (Brosnan and de Waal, 2003) The study revolves around the concept of unequal pay and also conducted with dogs, birds and chimpanzees. Two capuchin monkeys were placed in a see-through cage side by side to each other and asked to conduct a simple task of giving a stone back to the researcher. In the control study, the task was done and cucumbers were given to both as a reward, and continue doing so for the period of the task. This study was then conducted again, still asking for the stone, but this time one monkey was given a grape whilst the other received a cucumber. In the first trial, they both accept their reward. In the second trial, the monkey receiving the cucumber realises he is being treated unfairly and throws the cucumber back at the researcher. He still gives the stone back hoping for a grape but in his disappointment, receives and throws the cucumber away, and bangs on the cage. This can be said to be similar to human reactions, and how we would react to unfairness in rewards. This suggests that monkeys can perceive unfairness with aggression and anger the same way we as humans would.
Language plays, along with communication a big role in the logical capacity held by humans, and non-human animals. The human language has developed over time. “The early hominid communication system gave arise to the evolution of the human language, which apes relate to” (Armstrong et al, 1993). This suggests that there is an evolutionary link between human language and primates, hence leading to intelligence. However, we can conclude that humans are more intelligent than non-human animals, because of our advanced language ability that we as humans hold. The skill to understand and process language suggests a sense of intelligence as it shows that humans can understand each other and communicate verbally. Because of the primate’s inability to verbalise, it boosts ignorance in humans in relation to their intelligence.
Theory of mind (ToM) or mentalizing refers to the ability to understand that other people have a mental state, such as desires, intentions, beliefs etc. This allows humans from an early age to view the world from another perspective and have a theory of another person’s feelings or motivations. It also said that non-human animals can have a Theory of mind also. But before concluding that an animal is in possession of a theory of mind, other alternatives must first be ruled out. An example of supposed Theory of mind is the deceit in this baboon’s study (Byrne and Whiten, 1985). A strong baboon abused another younger baboon. The adults in the troop approached the baboon named Melton to punish his behaviour. Instead of showing compliance or running away, Melton stood on his hind legs and looked around, as if he had seen a predator. The adults stopped and looked in the same direction. Because of this behaviour shown by Melton, he had avoided punishment. Whilst Melton may have pretended to avoid punishment, he may have seen something that he mistook as a predator, or he may have even learned from previous experience that adopting the predator- warning behaviour, he can avoid punishment. Melton’s cognitive ability to manipulate the other monkeys shows a presence of advanced intelligence, which is seen in humans. This observational study can suggest but does not confirm Theory of mind in non-human animals. It is not only the Theory of mind approach that displays a comparable basis of intelligence between the two.
The mind of non-human animals and human with evidence do show a shared level of intelligence. The use of tools suggests there is a close link between humans and non-human animal’s minds. (Beck, Burghardt, Shumaker, Walkup, 2011) This can be seen in the study done by Biro et al (1993), where he found that Bossoer Chimpanzee’s used a third stone in the process of cracking open a nut, to act as a wedge. This was seen to be the same as a boy from a tribe in Bossou did.
In conclusion, the areas of intelligence must all be taken into consideration when judging intelligence. These aspects can be narrowed down to communication, social cognition and personal characteristics. We can conclude that intelligence in these different aspects can be compared. However, the matter of fact if non-human animals hold the intelligence which is level to that of humans is still debatable.