How monkeys mirror human irrationality

Interesting talk. I have two criticisms regarding the concepts involved.

1)

While it is true that humans can have trouble with making decisions which involve calculating "expected values" as in the double or nothing $ games mentioned in the video, there often are more reasons for accepting or declining a certain risk than can be mathematically captured. (For example I might be so desperate for *any* money that I cannot take the risk of possibly not getting anything if I enter the double/nothing bet.)

Here is an example of a game in which it is mathematically correct (but "real-world wrong") to bet any amount of money:
http://en.wikipedia.org/wiki/St._Petersburg_paradox

2)

Monkeys are not rational beings for they can give no reasons for their actions. (Which does not make them irrational beings.) So the use of the term "rational" here is misleading if it is used to suggest analogies between the minds of humans and other animals. Any being creditable with rationality can also be credited with accountability for its actions. But we do not hold monkeys, or any other animals save humans, accountable for what they do.

To prevent misunderstandings: "Economic rationality", that is, "getting the most out of the deal", is another matter. This use of "rational" is different from the philosophical one and refers to a technical concept of economy (which may or may not be psychologically motivated).

When humans make a wrong choice in one of the $ games from the talk, we may call that choice irrational because we can give a reason (in the form of a mathematical exposition) why it would have been better to choose differently. But while we may call a monkey's wrong choice "economically irrational" from our perspective in the sense described above, it makes no sense to attribute irrationality to the animal itself or to its mind.

Santos's experiments are of course about similarity in behaviour of humans and monkeys, not about similarity in reasoning. But the temptation to illicitly extend these results to the domain of the mind can be seen when she asks the "vexing" question as to how it is possible that there has been no evolution concerning choicemaking of this type in millions of years. In fact that has occured with the evolution of language, which makes reasoning possible. The fact that humans do not always excercise that power to its fullest extent is no more surprising than the fact that most people do not become world class athletes.