Differences in delay discounting between smokers and nonsmokers remain when both rewards are delayed

Abstract

Rationale

When offered a choice between a small monetary reward available immediately (SmallNow) versus a larger reward available after a delay (LargeLater), smokers select the SmallNow alternative more than nonsmokers. That is, smokers discount the value of the LargeLater reward more than nonsmokers.

Objectives

To investigate whether this group difference was due to smokers overweighting the value of rewards available immediately compared with nonsmokers, we examined whether the group difference was also seen when both alternatives were delayed, i.e., when choosing between a SmallSoon reward and a LargeLater reward.

Methods

In Experiment 1, smokers and nonsmokers completed a task including SmallNow versus LargeLater choices and SmallSoon versus LargeLater choices. In Experiment 2, smokers and nonsmokers completed the same task but with hypothetical choices.

Results

Analyses using hyperbolic and double exponential (β–δ) models replicate prior findings that smokers discount the LargeLater reward more than nonsmokers when the smaller reward is available immediately. The smoker–nonsmoker difference was also seen when the smaller reward was slightly delayed, though this effect was primarily driven by heightened discounting in male smokers. However, for potentially real rewards only, this smoker–nonsmoker difference was significantly reduced when the smaller reward was delayed.

Conclusions

The smoker–nonsmoker difference in discounting is not confined to situations involving immediate rewards. Differences associated with potentially real versus hypothetical rewards and gender underscore the complexity of the smoking–delay discounting relationship.

Appendix 1 Instructions received by participants

Experiment 1

This task has 210 questions. For each question, you can choose between two options by clicking on it using the computer mouse. You can change your selection as often as you like and there is no right or wrong answer — we are interested in your personal preferences. Once you have finally decided which option you prefer you can register your preference and go on to the next question by clicking on the “next question” box.

You will make choices between two amounts of money. One or both of the amounts of money will be available after a delay.

Remember, at the end of the task, one of the questions that you answered will be chosen at random. You should answer all of the questions on the task honestly, because you will actually receive whatever you chose on that question. If you chose “money now” you will receive that amount of money at the end of the task and if you chose “money later” you will actually have to wait before receiving the money.

Please try the demonstration below. When you are ready to begin the task, click on the “begin task” box.

Experiment 2

This task has 210 questions. For each question, you can choose between two options by clicking on it using the computer mouse. You can change your selection as often as you like and there is no right or wrong answer — we are interested in your personal preferences. Once you have finally decided which option you prefer, you can register your preference and go on to the next question by clicking on the “next question” box.

You will make choices between two amounts of money. One or both of the amounts of money will be available after a delay. Imagine that the choices you are making are real — that if you choose “money now” you would receive that amount of money at the end of the task and that if you choose “money later” that you would actually have to wait before receiving the money.

Please try the demonstration below. When you are ready to begin the task, click on the “begin task” box.