Sunk costs are irrecoverable investments that should not influence decisions, because decisions should be made on the basis of expected future consequences. Both human and nonhuman animals can show sensitivity to sunk costs, but reports from across species are inconsistent. In a temporal context, a sensitivity to sunk costs arises when an individual resists ending an activity, even if it seems unproductive, because of the time already invested. In two parallel foraging tasks that we designed, we found that mice, rats, and humans show similar sensitivities to sunk costs in their decision-making. Unexpectedly, sensitivity to time invested accrued only after an initial decision had been made. These findings suggest that sensitivity to temporal sunk costs lies in a vulnerability distinct from deliberation processes and that this distinction is present across species.
Bibliographical noteFunding Information:
We thank the Redish, Thomas, and MacDonald laboratories for assistance. Funding: R01 DA019666 (M.J.T.), R01 DA030672 (A.D.R.), R01 MH080318 (A.D.R.), R01 DA041808 (M.J.T.), R01 MH084861 (A.W.M.), MnDRIVE Neuromodulation Research Fellowships (B.M.S.), the Breyer-Longden Family Research Foundation (M.J.T.), MSTP NIGMS 5T32GM008244-25 (B.M.S.), GPN NIGMS 5T32GM008471-22 (B.M.S.), K02 DA035459 (M.J.T.), F30 DA043326 NRSA (B.M.S.), F31 DA040335 NRSA (S.V.A.), and F32 DA038392 NRSA (B.J.S.).
2017 © The Authors.