Gerd Gigerenzer, cognitive scientist, who directs the Max Planck Institute for Human Development in Berlin, in the book “Learning to Risk” tells how we make decisions in an uncertain world.

Among the different concepts presented, he distinguishes between:

- risk: a state of the world (an event that can take place) in which all information, alternatives, consequences and probabilities are known. It is the world of lotteries and gambling games.

- uncertainty: all the other states of the world. The world of uncertainty is immense compared to that of risk.

Not always it can be easy to recognize how it's uncertain the situation in which we find ourselves and it is therefore possible to confuse risk with uncertainty. This can have deleterious consequences, as the story of Mario and Turkey tells us.

Turkey is a nice 20 kg turkey.

Mario bought Turkey at the market in March. He took it home and put it in the garden.

The first day Turkey was very sad because he had been separated from his brothers and did not know what to expect from this big man who had first placed him in a cage, then put him in the trunk of the car and then  transported home.

Mario freed Turkey in the garden in front of the house. A great garden. With many flowers, plants, a beautiful green grass.

The first day Mario brought some very good grains to Turkey. And so he did for all the following days.

After a few days, Turkey is calm.

He made an easy calculation using the Laplace Sequence rule (conditional probability):

p = n + 1 / n + 2      that's, it has calculated the probability that something will happen again if it has already happened n times

where: n = number of days Mario brought food to Turkey

• after the first day the probability is:  1 + 1/1 + 2 = 0.67

• after 30 days: 0.97

• after 60 days: 0.98

• after 8 months (240 days): 0.99

Turkey believes it is moving towards certainty. It is certain that Mario will bring him food every day and will have a long and happy life in that luxuriant garden.

When his friends come to visit him, Mario takes them to the garden and proudly shows them Turkey. And everyone: "Mario, what a beautiful turkey, how fat it is, it will certainly be very good too!"

And Turkey thinks: “Mario loves me very much, he shows me to all his friends. And his friends how kind they are …, how many compliments…. I am happy!"

Summer is over, autumn has begun and now we are in November. Turkey is happy: a great season. Many colors ……

Tomorrow will be Thanksgiving, Mario will not bring the grain to Turkey.

But Turkey does not know this. Unfortunately, he lacks this information. And that will have deleterious consequences for him.

This is the Turkey Illusion: mistaking a world of uncertainty for a world of known risk.