Here is another set of numbers. Now find another person and ask that person to estimate the answer for version B within five seconds.

B: 1 x 2 x 3 x 4 x 5 x 6 x 7 x 8

You will probably discover that the second person gave you a smaller answer than the first, and both people gave figures well below the real answer (which is 40,320).

What happens is that the first number of the series biases the person’s thinking. This number anchors the person’s thought process and unduly influences the estimate they make for the calculation. The first series starts with a higher anchor “8” than for the second. When researchers carried out an experiment of these two questions, the average estimate for the first series was 3200 compared to only 300 for the second.

Both estimates are well below the correct answer because both series as a whole are made up of small numbers which biases the estimates to fall far below the true answer. In fact, you can bias a person’s reasoning by giving them an anchor that has nothing to do with the problem. Ask a person for the last three digits of the person’s telephone number. Add 400 to this number and then ask, “Do you think Attila the Hun was defeated in Europe before or after X (X being the year you got by adding 400 to the telephone number)?” Don’t say whether the person got it right (the correct answer is A.D. 451), and then ask, “In what year would you guess Attila the Hun was defeated?” The answers you get will vary depending upon the initial number you got adding 400 to the person’s telephone number.

The strength of the anchoring effect was further demonstrated by an experiment involving the estimation of the value of a house for sale. All subjects were given a tour of the house in question and identical information about it, except for the listing price, which were different, some high and some low. The prices varied 4% or 12% above or below the house’s appraised value. The researchers found that the listing price significantly biased the estimates given by the subjects, even the most experienced real estate agents.

The subjects anchored their estimated value of the house to their belief about the listed price. The estimates confirmed their belief about the accuracy of the listed price. Now consider what happens when you read these three words:

thief careless prison

We immediately visualize a story about a thief who makes a mistake and ends up in prison. We do this even though there is no grammatical connection between the words, because it confirms what we’ve come to believe happens to thieves who are careless.

Human understanding, when someone has a belief, forces everything else to add fresh support and confirmation. A teacher who believes that she has a class of “stupid” students will communicate expectations such that the children behave stupidly. She confirms her theory by asking them questions and eliciting stupid answers or puts them in situations where they behave stupidly. The theory-in-use is self-fulfilling. Similarly, a manager who believes his subordinates are passive, dependent, and require authoritarian guidance rewards dependent and submissive behavior. He tests his theory by posing challenges for employees and eliciting dependent outcomes.