Study leader Chuck Martin of the University of New Hampshire had 50 students observe shopping behavior throughout the New Hampshire Seacoast. Surveys were also conducted.

Martin found cognitive skills such as self-restraint, the ability to think before acting, and flexibility, the ability to change course in the face of set-backs, affect shopping styles. Observers found shoppers divided into four categories:

-- High flexibility are those who browse extensively and are open to suggestions such as buying a generic, less-costly version or trading up.

-- Inflexible are "on a mission" -- coming in for one item and leaving if it is not there.

-- High restraint customers may browse extensively and comparison shop, but will also leave empty handed if they don't find exactly what they want.

-- Low-restraint are the true impulse buyers who look at products randomly and often exhibit the "oohh" factor upon spotting a clearance rack.

"These impulse and non-impulse behaviors in shoppers can be identified in less than a minute, which could instantly indicate to a salesperson who is most likely to listen to their sales advice and who is not," Martin said in a statement.