One thing you have come to expect when shopping is that you'll come home with most of the things you intended to get on your trip as well as a few things that you did not leave the house expecting to buy. I used to go to the hardware store to get light bulbs or air conditioner filters and come home with a new tool or extra plants for the garden. Somehow, it felt like those other items just leapt into the cart.
Sometimes it doesn't matter if you pick up a few extra items at the store, but other times those impulse purchases can get you into trouble. For one thing, if you are trying to keep to a budget, buying things on impulse may break the bank. Also, there are times when the things you buy on impulse are not so good for you. Those extra cupcakes at the supermarket probably look better on the shelf than on your waistline. Finally, some of those things you buy never get used. I still have a few tools on the shelf that seemed much more crucial to own when I bought them than they ever have since.
What can you do to protect yourself from this sudden desire to buy?
In one clever study published in a paper in the journal Organizational Behavior and Human Decision Processes in 2002, Dan Gilbert, Michael Gill and Tim Wilson stopped people before the entered a grocery store. Only those who did not bring a list to the store were allowed to participate. Everyone began by listing what they intended to buy at the store that day and giving that list to the experimenter. Before entering the store, half the people were given a muffin to eat, and the other half were not. So, half the people were definitely not hungry, while the others were at least a little hungry. Those people who ate the muffin bought many fewer things that they did not intend to buy than those people who were hungry. So, going to the store hungry tends to make you purchase things that you did not intend to buy.
So what can you do if you happen to go to the store hungry? There were two other groups in this study. These groups were given their list of intended purchases before going into the store. Again, one group ate a muffin and one did not. The group that had the list and was hungry did not buy more items than they intended to buy than those who at the muffin and had a list. That means that having a shopping list is your first protection against impulse buying.
The next thing you can do to protect yourself from impulse purchases is to pay with cash rather than credit cards. Manoj Thomas, Kalpesh Kaushik Desai and Satheeshkumar Seenivasan published research in the June 2011 issue of the Journal of Consumer Research examining purchases by 1,000 households at a grocery store. The purchases were tracked with the data that comes from using a loyalty card at the store. All households, regardless of the method of payment, tended to buy the same amount of healthy food. But, those households who paid with credit or debit cards tended to buy more junk food than those who paid with cash. This study (along with some other experiments described in that research paper) demonstrates that paying with cash decreases the number of impulse purchases you make.
The third suggestion for avoiding impulse purchases is to bring a friend to the store. There is a lot of good evidence that your social network has a big influence on your behavior. A 2007 paper by Nicholas Christakis and James Fowler in the New England Journal of Medicine found that people who have many friends that are obese are far more likely to be obese themselves than people who have few friends that are obese. Part of the reason for this effect of networks is that friends and family members help each other avoid temptations.
If you are concerned about your impulse purchases, bring a friend shopping with you. Shop together with a friend at the grocery store. When you go out to buy clothes or a big-ticket item like a car or jewelry, take someone along who is not going to benefit from your purchase.
The reason that having a friend along is helpful is that as you get more engaged with a purchase, you start to get more positive feelings. Those positive feelings make everything in the store look better to you. A friend who is just along for the ride is not going to be as strongly affected by this purchase as you. That friend can serve as your external conscience. When you pull out another outfit that you do not really need, that friend can stop you.
Of course, to make this plan work, you have to agree to let your external conscience be your guide.
So remember, if you want to rein in impulse purchases: 1) Bring a list to the store, 2) shop with cash and 3) bring a friend.
Follow Art Markman, Ph.D. on Twitter: www.twitter.com/abmarkman