We use an experiment to compare a theory of risk-aversion and a theory of spite as an explanation for overbidding in auctions. As a workhorse we use the second-price all-pay auction. Both risk and spite are used to rationalize deviations from risk-neutral equilibrium bids. We exploit that equilibrium predictions in the second-price all-pay auctions for spite are different than those for risk-aversion. We find that spite is a convincing explanation for bidding behavior for the second-price all-pay auction. Not only can spite rationalize observed bids, also our measure for spite is consistent with observed bids. (C) 2021 Elsevier Inc. All rights reserved.