Last January, I celebrated the end of my sabbatical with a trip to a tropical paradise to conduct research, right before my next teaching term began. This enabled me to trade the middle of winter in south Texas for this:

Paradise “lost”.

To prepare for my forthcoming blog deadlines (and to avoid procrastination in its finest form – namely, waiting to get the source the day before my deadlines), I selected all of my spring target articles in January prior to my research trip.

The first two were completed on schedule with one being mostly completed well before its deadline (a rare event known as “precrastination”) and the other requiring a reminder from my intrepid editor, Stephan Lewandowsky, and some scrambling on my end to complete the article while conducting research in the above tropical paradise (“procrastination”).

Waiting on Dolphins or Buckets?

In January, “precrastination” did not exist in my vernacular although procrastination was my state of mind as it was much easier to hang out with dolphins than write a blog post.

I have since learned that precrastination is the “tendency to complete, or at least begin, tasks as soon as possible, even at the expense of extra physical effort.” Coined by David Rosenbaum and his colleagues in 2014, these researchers asked human participants to complete a task that required them to pick up a bucket and carry it to the end of an alley, 16 ft from the starting point. The interesting part was in all nine experiments, whether the bucket was empty, filled with 3.5 lbs or 7 lbs of pennies, or whether it was on the left or the right, did not matter as much as how near or far the bucket was from the starting point.  Surprisingly, the majority of the participants in each experiment picked up the bucket closest to the starting point and carried it for the remaining distance to the end line.

This behavior was counterintuitive, especially based on most of our human experiences with onerous tasks – put off the unpleasant task (“carrying a bucket, especially a heavy one”) as long as possible. Rosenbaum and his colleagues suggested that perhaps the participants were able to reduce their working memory load (i.e., “don’t forget to pick up the bucket before you get to the end line”) by completing a sub-goal (i.e., “bucket – check; next stop – end line”).

It’s Really about the Birds!

Edward Wasserman and his team decided to investigate whether pigeons also showed evidence of “precrastination” or procrastination. Wasserman and Brzykcy presented pigeons with a three-step task that was methodologically different from the human study in which “precrastination” was elicited, and although the pigeons learned the task, they procrastinated rather than “precrastinated,” as anticipated. We blogged on this study by Wasserman and Brzykcy when it first came out in 2015.

In a recent article published in the Psychonomic Bulletin & Review, which is highlighted in this post, Thomas Zentall, Jacob Case, and Danielle Andrews argued that the methodological differences between the human task and the three-step pigeon task used by Wasserman and Brzykcy were problematic, and rather than evoking precrastination, perhaps the procedure triggered a delay reduction as proposed by Fantino in the late 60s.

That is, maybe procrastination is related to the conditioning of a cue (i.e., a conditioned reinforcer, such as sitting at a computer with a word on the screen) that occurs just prior to experiencing the highly reinforcing feeling of completion when a task is finally completed (e.g., this article). Precrastination may be valid, but the procedure used in the Wasserman and Brzykcy’s study may not have been the ideal methodology for the birds.

To test whether pigeons would procrastinate or precrastinate, Zentall and his team utilized a different experimental procedure in which the pigeons were tested using two sequences of events (i.e., concurrent chains).

The figure below illustrates the two chains of events that the pigeons chose between during their test sessions.

On each test trial, the pigeon were free to choose one of the two chains of events: If a pigeon pecked at the vertical line inside of the circle (in the blue box), then the “precrastination” schedule was activated (i.e., a blue light turned on and signaled a Fixed Interval of 5 seconds (FI 5 s). At the termination of the 5 s interval, a yellow light turned on to signal an FI 15 s schedule. Reinforcement was delivered at the termination of the second FI schedule. By contrast, if a pigeon pecked at the horizontal line inside of the circle (in the green box), then the “procrastination” schedule was activated (i.e., a green light turned on and signaled an FI 15 s; at the termination of the 15 s interval, a red light turned on to signal an FI 5 s schedule).  Reinforcement was delivered at the termination of the second, shorter time interval.

One attribute of fixed-interval schedules is that the first response after the scheduled interval leads to either the next interval or to reinforcement. Because pigeons, once trained on the FI durations, peck at a high rate at the end of each schedule, the actual intervals will be very similar to the interval scheduled by the experimenter.

The figure below provides a snapshot of the overall results. It plots the proportion of times that the pigeons preferred the “procrastination” schedule (i.e., they pecked the horizontal line in the green box, which triggered the FI 15 – FI 5 sequence):

It is clear that the pigeons generally liked to procrastinate. They put off the pecks that were required to trigger the next interval as long as possible.

Another, more detailed way of looking at the data is to consider the rate of pecks (per second). This is shown in the figure below, which refers to the first interval in the sequence as the “initial link” and the second interval as “terminal link”.

As the figure demonstrates, the pigeons pecked at the terminal link that was closest in time (“short”) to the reinforcement delivery (green box/red light from the earlier figure) significantly more rapidly, and correspondingly, they pecked significantly less often at the terminal link that was farthest in time (“long”) from the reinforcement delivery (blue box/yellow light from the earlier figure).

So why did the pigeons prefer to procrastinate? Zentall and his colleagues argued that the pigeons most likely paired the red light with the delivery of the reinforcement in the procrastination chain more so than they did the yellow light in the precrastination chain, thus creating a strong conditioned reinforcer for procrastination.

It was already suggested by Fantino in his earlier work, and echoed by Zentall and colleagues, that the conditioned reinforcer, or the cue used to signal that the reward is near or imminent, will be stronger the greater the reward. This set of studies is waiting to be performed.

Until Next Time. . .

Take my current experience: although I did not wait until the absolute last minute to write this post (except for the vacuuming and dusting that occurred prior to it), I waited long enough to allow the anxiety to build up. Since completing the article, my reduction in anxiety has been extremely gratifying, and like many others, I will likely continue to repeat this process again and again and again. At least my house will be clean!

Psychonomics article focused on in this post:

Zentall, T. R., Case, J. P., & Andrews, D. M. (2017). Procrastination in the pigeon: Can conditioned reinforcement increase the likelihood of human procrastination? Psychonomic Bulletin & Review. DOI: 10.3758/s13423-017-1409-2.