Over the past decade behavioural scientists have come up with some intriguing insights. In one landmark experiment, conducted in an upmarket grocery store in California, researchers set up a sampling table with a display of jams. In the first test they offered a tempting array of 24 different jams to taste; on a different day they displayed just six. Shoppers who took part in the sampling were rewarded with a discount voucher to buy any jam of the same brand in the store. It turned out that more shoppers stopped at the display when there were 24 jams. But when it came to buying afterwards, fully 30% of those who stopped at the six-jam table went on to purchase a pot, against merely 3% of those who were faced with the selection of 24.
The researchers repeated the experiment with chocolate as well as student essay topics and found similar results. Too much choice, concluded Sheena Iyengar of Columbia University and Mark Lepper of Stanford, is demotivating. Others have since come up with similar results from experiments with writing pens, gift boxes, coffee and even American 401(k) pension plans. (It is not all that way: German researchers, by contrast, found that shoppers were not put off by too much choice, whether of jams, chocolates or jelly beansthough this may be down to Germany's price-conscious shoppers and the sheer dreariness of the country's supermarkets.)