First came Classical Rationality, from Bayes theorem to multiple regression...and boy oh boy are they complicated! The theories stand up fine, following laws of human reasoning, these tools became 'normative and descriptive tools of inference and decision making' (Gigerenzer & Goldstein 1996). The problem was, they were too precise for us mere mortals. Human inference is biased and we make mistakes, research suggested that humans probably rely on heuristics more than laws of probability. We're aware of the laws of probability (they certainly exist) its more that we don't always follow them.
So along came Simon with his models of bounded rationality, introducing the idea that humans using an IP approach, satisfise (great word not a typo) rather than optimise and that minds should be understood relative to the environment. This vaguely defined model allows for all sorts of interpretations and interjections but, I think, makes an important point (which is backed up in Heuristic models) that the environment plays a part in JDM.
G&G (Gigerenzer and Goldstein), suggested the 'take the best' algorithm. A 5 step process where essentially all cues have values, working through the necessary steps a decision is reached when the cue with the highest positive ranking is found. I take a positive cue to be in a 'what I want' direction and a negative cue to be 'what I don't want' direction. They suggest that instances occur where 'less is more', ie 'not knowing' about 'a' means that 'b' has a higher value than 'a' therefore is chosen more readily. Tasks they cite in this research are 'inconsequential' (eg which town has the highest population), which takes me to another old saying "a little knowledge is a dangerous thing". In the event of a decision with consequences, would we be prudent to use such a method? Which, in turn, brings us back to the importance of the environment (expressing 'cirumstance' as 'environment' here), how much impact does it have on how we make decisions and what decisions we make?
Fast and Frugal models are based on structural relationships between cues and judgments. They are process models that do not search through all the information available nor do they integrate all information thus decisions are made using one cue only. Dhami and Ayton quite deftly support this theory in their study but close saying that whilst F&F models are descriptively and predictively valid, "they may lack prescriptive utility" (I am hoping to have more understanding of that statement this week). The matching heuristics model (F&F), suggests a person searches for and stops at the first cue with a critical value for a decision. This was compared with Franklins rule,where cues are weighted according to their influence on the decision, and the direction of the decision is dependant on the value of the sum of cue weights versus the threshold value (weighing up the pros and cons?). It was also compared with Dawes Rule, whereby each cue has a unit weight and the direction of decision is dictated by the number of cues of critical value versus the threshold value (Its got more going for it).
So how does that relate to real life? One would hope that in life and death situations one would weigh up all the pros and cons, take the most sensible, efficient approach which has the predicted best outcome for all concerned. However as noted the environment has a substantial impact on the way in which we make decisions...time is crucial to JDM processes, the quicker a decision is to be reached, the more likely we are to use a 'quick fix' heuristic model. Ironically these occasions are possibly those that require more not less thought.At the same time when confronted with an immediate danger the decision to 'run' definitely needs little thought!
It appears to me, being a mere novice at JDM, that there are many aspects that are influenced by other aspects of psychology, from individual differences in personality & cognitive processes to social background, & current social aspects. It would seem remiss to me, not to consider external influences on decision making processes as it would appear to be these 'human' aspects which dictate the appropriate model of decision making to person A at point B in time in situation C. I say this despite evidence that particular models have been empirically 'proven', because there is "nowt more unpredictable than man"
