Are Humans Rational? Are humans rational? The human species has well developed cognitive abilities compared to animals. These can be remarkable like language and many other communication systems. Our visual system provides us with excellent vital information for the environment. Besides, through thinking and problem solving, we have adapted the environment to suit us and developed science and technology. Surely, these are evidence of an advanced intelligence humans possess.
On the other hand, though, psychological research strongly suggests that humans are irrational. There is a mass of psychological evidence (Kahneman et al., 1982; Baron, 1988; Evans et al., 1993), which show many errors and biases in human reasoning and decision-making. Besides, everyday life provides us with supportive evidence for human irrationality. Smoking and drink driving is just a couple of them. How did humans achieve so much but are being irrational in so many experimental tasks and many aspects of life? Philosophers and psychologists, troubled by this paradox, suggest that there must either be something wrong with the experimental research as it is or researchers misinterpret the findings.
In 1996, Evans and Over proposed another possible solution to the paradox. They argued that there should be a distinction between the uses of the word rationality. They suggested two different uses of the word rationality, rationality1 and rationality2. Rationality1 is used when referring to the rationality on a personal level. In this case, rationality is satisfied when people successfully achieve the basic goals of survival and communication. Animals and humans share rationality1 that includes the use of early cognitive processes such as memory, perception, problem solving, learning and processes of adaptive and effective thinking. Rationality2, on the other hand, is impersonal and depended on actions based on logic or hypothetical thinking. Rationality2 is exclusive to humans.
Laboratory experiments use probability and logic theories to assess rationality2 and find people having difficulties in processing that type of information. An average person is claimed to be systematically wrong in deductive reasoning and judging probabilities. According to Nisbett & Borgida in 1975, psychological evidence have bleak implications for human rationality and man is not a reasonable intuitive statician and cannot handle probabilities or making predictions (Kahneman & Tversky, 1972). Found irrational2 in labs, people could still be rational1 in life. In a typical experimental task, participants will be given a set of information to evaluate and reach a conclusion.
This is where errors in evaluation or selection of conclusions in deductive problems appear because participants are likely to be influenced/biased by the believability of the conclusion. The belief bias effect, as it is called (Evans et al., 1993), is well established, replicable and is said to produce supportive evidence for human irrationality2. Peoples ability for adaptive and effective (rational1) thinking could be, to a certain extent, an unconscious process and could be responsible for the belief bias effect. The suggestion of unconscious cognitive processes implies that things that are habitual can be very influential, even when people are given instructions to disregard them on a task. In real life, people do not always use logic and probability theories to make a decision.
Past experience and individual factors are more likely to influence everyday decision-making. A rational decision would be based on hypothetical thinking and should be made after all the alternative actions are assessed and the most profitable one is chosen. If logic were applied to everyday issues such as smoking, decision-making would be much harder. For example, would it be irrational for a soldier in war to smoke? His health is in great risk already so why worry for long-term implications of smoking? Smokers admit that smoking is irrational but benefits (such as conformity and stress relief) should be taken into account when trying to judge based on logic. Besides, decision-making is subjective and no theory argues that long-term goals are superior to short-term ones (e.g. being healthy).
Humans are not likely to act based on hypothetical analysis of future events but to try to achieve immediate goals using past references. Errors in reasoning result from peoples difficulties to make decisions when they are uncertain and cannot use past references. Such situations include when estimating and balancing risks. Humans appear to be irrational in the area of risks. They seem extremely concerned of risks they know little about (e.g.
nuclear plant leakage) but enjoy everyday activities known to be dangerous (e.g. horse-riding). Poor performance on probability learning and understanding could explain humans behaviour to risks. People appear biased when responding to statistical or probability situations because we are limited to efficiently use hypothetical thinking and be rational2. Smokers ignore everyday statistical information of the damages smoking causes to health and many continue to drink and drive despite knowing the shocking statistical findings of accidents. People appear to omit themselves from the statistical group of smokers/drink-drivers and believe that the statistics do not apply in their case. Taylor and Brown (1988) suggested that normal people could be overconfident about succeeding in life compared to people with psychological disorders. On the other hand, people suffering from a psychological illness have been found to perform different probability judgements from healthy individuals.
People suffering from delusions are found interestingly studied for their cognitive abilities of thinking and reasoning. There is no substantial support, though, that delusions are the result of failure in logical reasoning but could be the result of right reasoning from wrong experiences, like hallucinations. People suffering from phobias sometimes realise that their behaviour is irrational since the elevator is not a real threat to them for example. But being rational2 does not help them lose their implicitly learned fear (and irrationality1), while behavioural therapy does. When a normative question like Are we rational? is made, reasoning is thought to result from an indivisible cognitive mechanism.
Scholl (1997) argues that the cognitive architecture of reasoning could consist of many different cognitive mechanisms. Evans & Over (1997) suggest that people have two different cognitive systems to reason. The implicit mechanism works unconsciously processing past references and results in rationality1. The explicit cognitive system is behind our limited ability to be rational2. The explicit system requires us to think hypothetically and assess probable situations.
Both uses of rationality are limited and research focuses on errors and biases in thinking, suggesting that humans are irrational. At the same time, human intelligence has successfully evolved to the point of trying to make computers think like humans. Humans can be rational and irrational through their lives. Humans make good decisions, as well as bad ones, everyday. Any limitations in our reasoning could be reduced with training on following the rules of logic. Thus, taking in mind we have highly adaptive intelligence, our ability to reason could improve.
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