If the human mind is indeed rationalizing rather than rational, how does this play out in the process of decision-making? In the 1980s German psychologist Heinz Heckhausen (1926-1988) developed what he called the Rubikon theory, a model that combines the different types of motivation before and after a decision into a unified model.
The first stage, the time before the person has made a decision, is called Deliberation. During this phase people tend to be open-minded about facts (e.g. the pros and cons of a particular decision) and realistic about their abilities.
Heckhausen calls the point of decision the “Rubicon.” This term is based on the historical event that started the Roman Civil war, which eventually led to Julius Cesar overthrowing the republic and declaring himself emperor. By crossing the river Rubicon with his army, Cesar overstepped the boundary set by the Roman senate, which made him an enemy of the state. Thus, the Rubicon has become a figure of speech indicating the point of no return, the point where a person makes a commitment to a certain course of action.
The Rubicon marks the point of transition from a deliberative to a volitional mindset. From now on, the person has set her mind on implementing the decision that was made. During the Planning and Action phases people are closed-minded. They tend to selectively focus on information that confirms their decision and helps them achieve the goal they have set for themselves. In contrast, they prefer to ignore or downplay anything that might cast doubts on their planned goals or their ability to reach them.
While pursuing their goals, they are also prone to have unrealistic perceptions of themselves and their abilities. They may under-estimate the likelihood of complications and overestimate their ability to control them.
During the post-actional or evaluation phase the motivation tends to shift, again. While people may still be biased to justify their decision, they might also become more able to draw objective conclusions even if this involves questioning their intentions and actions.