Are Human Beings Predictably Irrational?

Are Human Beings Predictably Irrational?

A Ted video by Dan Ariely, Are We in Control of Our Decisions? Provides an explanation of what it means to say that human beings are predictably irrational. He presents several examples that show that humans tend to make mistakes in their decision making and reasoning and worse is that sometimes it happens repetitively. He then demonstrates by the use of examples that while humans think they are making decisions, they are actually being influenced by external factors. Thus, based on the examples that Dan Ariely gives in his Ted video, and his explanations of them, by the phrase humans are predictably irrational, Dan Ariely means that human beings do not make decisions based on rational thought; at least they do not in most cases, contrary to how it has traditionally been assumed.

As an example, visual illusion can be used as a metaphor for rationality; and, if used, it can help demonstrate that humans are predictably irrational (TED 02:28-04:07). If a long table is placed adjacent to a short table and a photo of them taken, with the longer table positioned at a slight angle so as to fit the frame of the picture, visually, one is most likely decide (his audience generally did) that the vertical line along the longer table is longer than the horizontal line along the shorter table until measurement proves otherwise. In another use of illusion as a metaphor for irrationality, when observed, the same color on different faces a cube appear different until the rest of the cube is covered, in which case they turn out to be similar. The surprising fact is that in spite of the fact it has taken millions of years of evolution to develop human vision, we are still prone to being deceived by it.

Having seen that vision can be unreliable, the question is whether more mistakes can be made in cognitive illusion decision making. In a study that investigate the percentage of people that would be willing to donate their organs, countries that were more willing to donated were generally found to be geographically located close to each other (as cited in TED 05:08). While most people’s explanation of the outcome would be that the culture of those found to be most likely to donate was such that they had compassion for other humans, it turns out that the results depended on how the assessment of the willingness to donate was structured. The interviewer has a huge impact on our decisions.

In another study, conducted by Dan Ariely, the belief by people that their evaluation of other people’s attractiveness, and hence the decisions they are arrive at, are independent of anything else, showed the contrary to be true (TED   14:25). A person turned out to appear more attractive if a person who resembled them but was less attractive was around, even in situations where there was a third person who was more attractive than both of them.

The decisions we make come from outside ourselves, not from within. What people have is the illusion that they are making a decision rationally while in real sense they are doing it irrationally. It is what Dan Ariely calls being predictably irrational. As to whether there is truth in Dan Ariely’s argument, McKenzie argues that the advocators of humans being predictably irrational have simply been fooled by the evidence they obtain from the majority (236).


Works Cited

TED. “Dan Ariely asks, Are we in control of our decisions? ” Online video clip. YouTube.

YouTube, 19 May. 2009. Web. 6 May. 2015.


McKenzie, Richard B. Predictably Rational?: In Search of Defenses for Rational Behavior in

 Economics. Heidelberg: Springer, 2010. Print.