Pigeons prefer to invest early for future reinforcers

Five pigeons were trained in a series of conditions in which food was delivered after 25 responses, but only when a different (Investing) response had been made before the 25 responses had been completed. If an Investing response was not made, the 25 responses ended in blackout. In various conditions, effective Investing responses either had to be made before the first of the 25 responses, or anywhere within the 25 responses; and effective Investing responses either resulted in a stimulus change or did not. Pigeons Invested even when the consequences were temporally and spatially distant, but Investing was most likely when it produced an immediate stimulus change. When given the choice, pigeons preferred to make Investing responses at the beginning of a trial. These findings again demonstrate that behavior may be maintained by events that are separated in time and space from the present.