Wulfert E, Roland BD, Hartley J, Wang N, Franco C. Psychol Addict Behav. 2005 Sep;19(3):311-6.
People sometimes claim they gamble for excitement rather than money. The authors examined in a laboratory analog whether excitement is generated by the expectancy of winning money. Eighty male undergraduate students watched a videotaped horse race with an exciting neck-to-neck finish. Half bet $1 for a chance of winning $7 if they picked the winning horse; the other half predicted the winning horse without wagering. Winning and losing were experimentally manipulated.
Participants with a chance to win money showed greater heart rate (HR) elevations and reported more subjective excitement while watching the race compared with those who did not wager. Of students who wagered, the winners showed higher HRs after the end of the race than did those who lost, even though differences in subjective excitement were not statistically significant.
The findings suggest that the expectancy of winning money is an important contributing factor to the excitement associated with gambling.