Are normative probabilty judgments a "system two"-operation?

Sammanfattning: Previous research on human judgment and decision making has demonstrated systematic and predictable biases of judgment in experimental settings. One example of this is the tendency to intuitively violate the conjunction rule - a simple rule of probability. This was well illustrated in the famous Linda-problem. (Tversky & Kahneman, 1983). According to the dual-process theory of reasoning, (Kahneman, 2011) reasoning fallacies such as the conjunction fallacy occurs when people fail to use analytic reasoning and instead overly rely on their intuition. The dual process theory proposes that cognitive processes underlying our intuitive impulses and our conscious reasoning constitutes two different modes in the mind –system 1 and system 2- and that the intuitive system 1 are not able to compute probabilities. Furthermore, it is assumed that processes that are labeled system 1 are fast whereas system 2 are thought to be slow. We tested these time course assumptions of dual process theory in a within-subject design by comparing response time latencies between conjunction fallacy judgments and accurate probability judgments. The results showed that inducing accurate responding did not result in delayed response latency. This indicates that making accurate probability judgments does not require more processing time which goes against what would be expected by the dual-process framework.