Dual process models

Dual process models or dual process theory provides an account of how a phenomenon can occur in two different ways, or as a result of two different processes. Often, the two processes consist of an implicit (automatic), unconscious process and an explicit (controlled), conscious process. Verbalized explicit processes or attitudes and actions may change with persuasion or education; though implicit process or attitudes usually take a long amount of time to change with the forming of new habits. Dual process theories can be found in social, personality, cognitive, and clinical psychology.

History
The foundations of dual process theory likely comes from William James. He believed that there were two different kinds of thinking: associative and true reasoning. James theorizes that empirical thought was used for things like art and design work. For James, images and thoughts would come to mind of past experiences, providing ideas of comparison or abstractions. He claimed that associative knowledge was only from past experiences describing it as “only reproductive”. James believed that true reasoning was useful for “unprecedented situations” in which using reasoning to overcome obstacles such as navigation could be overcome with reasoning power of being able to use a map.

Steven Sloman produced another interpretation on dual processing. He believed that associative reasoning takes stimuli and divides it into logical clusters of information based on statistical regularity. He proposed that how you associate is directly proportional to the similarity of past experiences, relying on temporal and similarity relations to determine reasoning rather than an underlying mechanical structure. The other reasoning process in Sloman's opinion was of the Rule based system. The system functioned on logical structure and variables based upon rule systems to come to conclusions different from that of the associative system. He also believed that the Rule based system had control over the associative system, though it could only suppress it.

Daniel Kahneman provided further interpretation by differentiating the two styles of processing more, calling them intuition and reasoning. Intuition (or system 1), similar to associative reasoning, were determined to be fast and automatic, usually with strong emotional bods included in the reasoning process. Kahneman said that this kind of reasoning was based on formed habits and very difficult to change or manipulate. Reasoning, or system 2 was slower, and much more volatile, being subject to conscious judgments and attitudes.

Dual process models are very common in the study of social psychological variables, such as attitude change. Examples include Petty and Cacioppo's Elaboration Likelihood Model and Chaiken's Heuristic Systematic Model. According to these models, persuasion may occur after either intense scrutiny or extremely superficial thinking. In cognitive psychology, attention and working memory have also been conceptualized as relying on two distinct processes.

Dual process learning model
Ron Sun proposed a dual process model of learning (both implicit learning and explicit learning). The model (named CLARION) re-interpreted voluminous behavioral data in psychological studies of implicit learning and skill acquisition in general. The resulting theory is two-level and interactive, based on the idea of the interaction of one-shot explicit rule learning (i.e., explicit learning) and gradual implicit tuning through reinforcement (i.e. implicit learning), and it accounts for many previously unexplained cognitive data and phenomena based on the interaction of implicit and explicit learning.

Duplex model
Roy Baumeister recently surveyed the research literature and proposed a dual process or "duplex model" of the mind. According to this model, humans typically operate on two levels, conscious and automatic. The conscious mind is effortful and limited in capacity, whereas the automatic mind processes many things simultaneously and independently of each other. An example would be walking and chewing gum (automatic), while having a conversation with a friend (conscious). Automatic events are often but not necessarily outside of conscious awareness. Baumeister's approach is noteworthy as a broad attempt to integrate different areas of research into a unified model of psychology.

Dual coding
Using a somewhat different approach, Allan Paivio has developed a dual-coding theory of information processing. According to this model, cognition involves the coordinated activity of two independent, but connected systems, a nonverbal system and a verbal system that is specialized to deal with language. The nonverbal system is hypothesized to have developed earlier in evolution. Both systems rely on different areas of the brain. Paivio has reported evidence that nonverbal, visual images are processed more efficiently and are approximately twice as memorable. Additionally, the verbal and nonverbal systems are additive, so one can improve memory by using both types of information during learning.