I'll agree that it does seem like there is more than simple information gain going on here though. Perhaps there are other factors, such as the insertion of an element of competition?

Certainly seems possible. I admit I tend to announce the time it took to find something that someone failed to as part of showing off and elevating myself, so it would be no surprise if the recipient felt shamed and inflamed into looking better - the difference between peak and average performance might explain the differential.