101 YEARS OLD AND STILL ENJOYING IRRATIONALITY...

FROGS, I was delighted to discover the other day, are just as irrational as humans. I learnt this from reading a research paper published in Science journal in 2015 under the title “Irrationality in Mate Choice Revealed by Tungara Frogs”. Before jumping ahead with frogs, let’s have a human story:

A man went into a café and asked what sandwiches they had. The waitress told him they had prawn or chicken and he said “I’ll have prawn, thank you.”

The waitress then remembered something and said, “Oh, I forgot: we also have smoked salmon.”

“Oh,” said the man, “in that case I’ll have chicken.”

When I was first told this story, it was given as a humorous example of human irrationality, which puzzled me a little as I didn’t feel it was irrational at all. After reading the paper mentioned above, I am delighted to report that frogs would not find it perplexing either.

The froggy experiment involved playing croaks of males through loudspeakers to female frogs and seeing which ones they chose. Frogs can judge the attractiveness of other frogs from the pitch and frequency of their croaks, so by manipulating the croak rate, the experimenters could make croaks more or less attractive.

First, they would test a female with croaks A and B to see which she chose, then they would introduce croak three, which was less desirable that either A or B but acted as a decoy. Amazingly some females were found to choose A over B when only those were heard but to choose B ahead of A when C was also offered.

This was also found to be the case if the loudspeaker playing croak C was placed on the ceiling and was therefore unobtainable to the female frog. Sadly we do not know whether the man in the cafe would still have chosen chicken if the smoked salmon sandwich had been on the ceiling but otherwise the frogs seem to have behaved in much the same way as him.

Humans have been shown to do something similar when selecting wines in supermarkets or restaurants. Offered A (cheap) or B (medium price), they will go for the cheaper option to save money, but if C (expensive) is also available, they will often choose B, decoyed into thinking that they are now saving money by not buying C.

The smoked salmon, in any case, is much nicer than the prawn but probably much more expensive, but the chicken is still as enticing as ever, so I’ll have that, thank you very much.

Basically it all comes down to the intransitivity of human (and frog) preferences: you may prefer A to B and prefer C to A but still pick B over C when given the choice. It’s the old Matchmakers (M), After Eights (AE), Bendicks Bittermints (BBM) dilemma: AE is preferred to M as they are tastier and only a bit more expensive; BBM is preferred to AE for exactly the same reasons; but given the choice between BBM and M, I choose M as they are tasty enough and much cheaper. Frogs, as far as I know, do not eat chocolate, which makes their life much simpler.