The giving season: food and money -an evolutionary link?

This short note from the Editor's choice section in the Dec. 22 issue of Science:

"Although the giving of gifts is a common activity at this time of year, giving a gift certificate has become an allowable substitute for giving money, which is generally regarded as unseemly. In order to explore whether money can serve not only as a useful instrument (for the purchase of material goods) but also as a valued resource, Briers et al. (Psychol. Sci. 17, 939 (2006) have carried out a series of experiments to see whether an unfulfilled desire for food (or money) might make one more tight-fisted (or more voracious). People who were hungry behaved less generously toward a charity (Médecins Sans Frontières) and in public goods games than those who had just eaten cake; conversely, people who were told to imagine being desirous of a substantial payoff (being in such a state was confirmed by how much their estimates of the size of a coin were skewed to be larger than actual) consumed more M&M's than those who were focused on a modest windfall. These results linking the rewarding character of food to that of money dovetail neatly with a recent study (Vohs et al., Science, Reports, p. 1154, 17 November 2006) that demonstrated money's value as a means of enhancing one's self-sufficiency and social independence.

Here is the abstract from Briers et al.:
This report attempts to provide an evolutionary explanation for humans' motivation to strive for money in present-day societies. We propose that people's desire for money is a modern derivate of their desire for food. In three studies, we show the reciprocal association between the incentive value of food and of money. In Study 1, hungry participants were less likely than satiated participants to donate to charity. In Study 2, participants in a room with an olfactory food cue, known to increase the desire to eat, offered less money in a give-some game compared with participants in a room free of scent. In Study 3, participants' desire for money affected the amount of M&M's® they ate in a subsequent taste test, but only among participants who were not restricting their food intake in order to manage their weight.