In his book, “The Power of Persuasion”, psychologist Robert Levine talks about a recent series of experiments, in which social psychologists, Sheena Iyengar and Mark Lepper, demonstrated that too many choices could be overwhelming and counter-productive.
In their study, a group of Columbia University chocolate lovers were given a choice of six different flavors of Godiva chocolate and asked to taste a sample of any one. A second group was asked to choose among thirty different flavours. Subjects given the extensive flavour choices rated their selection as less tasty, less enjoyable and less satisfying than did the limited choices group. The thirty-flavour subjects expressed more regrets about their selection and were less likely to choose chocolate as payment for participating in the experiment.
In another experiment, Iyengar and Leppar set up a jam-tasting table in Draeger’s supermarket, an upscale grocery store in Menlo Park, California, with a reputation for extensive selection. In one condition, the researchers offered shoppers tastes of six different exotic flavours of Wilkin & Sons jam. In a second condition, they offered twenty-four different Wilkin & Sons flavours. Easy choices like strawberry and raspberry were left out. The displays were rotated hourly over two Saturdays. Once again, Lepper and Iyengar found, shoppers were won over by the smaller selection. 60% of the customers who passed by the 6-flavour table stopped for a sample, compared with 40% of customers who passed by the 24-flavour table.
Apparently, the human threshold for number of choices is 6. Beyond this number, the law of diminishing returns sets in.
In a related story I found in this blog of Jonah Lehrer :
Stanford professor Baba Shiv invented an experiment where he manipulated the "cognitive load" of subjects. Shiv gave half of the subjects a two-digit number to memorize (low load), while the other half were given a seven-digit number (high load). Subjects were then instructed to walk to another room in the building. On the way they passed by a table at which they were presented with a choice between a caloric slice of chocolate cake and a bowl of fruit salad. Fifty-nine percent of the people trying to remember seven digits (high load) chose the cake, while sixty-three percent of the two-digit subjects (low load) chose the fruit salad. In other words, having people memorize an extra five digits made them exhibit significantly less self-control.
Why did the number of digits have such a strong effect? Shiv speculates that the effort required to memorize seven numbers drew cognitive resources away from our ability to control our urges. Having to remember seven numbers occupied neurons that would otherwise help us decide what to eat, which causes us to become more reliant on our impulsive emotions.
As my loyal readers know, I don’t write book reviews just for the heck of it. I always look for some learning from each book and make it a point to enlighten and educate my readers. So, what I want to share with you this time is this.
In supermarkets, in various parts of the world, University professors are going around with crates of jam bottles and tins of milky chocolates and, in the name of research, are giving away free samples, to all and sundry, while you and I have been frittering away our time on the computer and reading up on some mind-numbing nonsense.
Quick. Memorise a 7-digit number, get out of that chair right now and head for the nearest grocery story. 24 different and exotic flavours of ‘Wilkin & Sons’ jams and 32 different types of Godiva chocolates are up for grabs, free of cost.


