Retain Your Knowledge: Decision Making and Hunger Does hunger improve strategic decision making? That is, if you are hungry are you more likely to make a favorable decision when the outcome of your decision is uncertain (as in business decisions)? To test this theory, researchers randomly divided 30 normal weight individuals into two groups. All subjects were asked to refrain from eating or drinking (except water) from 11 P.M. on the day prior to their 9 A.M. meeting. At 9 A.M., the subjects were randomly assigned to one of two groups. The subjects in Group 1 were fed breakfast while the subjects in Group 2 were not fed. All subjects were administered a computerized version of an exam that assesses complex decision making under uncertain conditions. The assessment consisted of subjects choosing cards from four decks marked A, B, C, and D. Cards in decks A and B had a point value of 100 while cards in decks C and D had point values of 50. However, deck A had penalty cards that deducted points between 150 and 300; deck B had one penalty card of 1250; deck C had penalty cards between 25 and 75 points; deck D had a single penalty card of 250 points. So, decks A and B had stiffer penalties over the long haul than decks C and D and in the long haul, decks C and D resolted in more points than decks A and B. In total, the subjects would select 100 cards. However, the response variable was the number of cards selected from decks C and D out of the last 60 cards selected. The thinking here is that after 40 card selections, the subjects would be aware of the advantage of decks C and D. The researchers administered a Barret Impulsivity Scale to be sure the two groups did not differ in terms of impolsivity (e.g., “I do things without thinking”). There was no difference in impulsivity, age, or body mass index between the two groups. Before the exam, subjects were asked to report their level of hunger and it was found that Group 2 was significantly more hungry than Group 1. After analysis of the data, it was determined that the mean number of advantageous cards (decks C and D) selected by the subjects in Group 2 was 33.36 cards while the mean was 25.86 for the subjects in Group 1. The researchers concluded that hunger improves advantageous decision making.


b. Identify the experimental units.

Verified step by step guidance

1. Recall that experimental units are the individual entities on which the experiment is conducted and to which treatments are applied.
2. In this study, the researchers randomly divided 30 normal weight individuals into two groups and applied different treatments (fed breakfast or not fed) to these individuals.
3. Therefore, the experimental units are the 30 normal weight individuals participating in the study.
4. Each individual is observed for their decision-making behavior after the treatment, making them the basic units of analysis.
5. So, the experimental units are the individual subjects who were assigned to either the fed or unfed group.

Key Concepts

Experimental Units

Experimental units are the individual subjects or entities on which the experiment is conducted and data are collected. In this study, the experimental units are the 30 normal weight individuals who were randomly assigned to the two groups and whose decision-making performance was measured.

Random Assignment

Random assignment is the process of allocating experimental units to different treatment groups by chance, ensuring that each unit has an equal probability of being placed in any group. This helps control for confounding variables and allows for causal inference about the effect of hunger on decision making.

Response Variable

The response variable is the outcome measured to assess the effect of the treatments. Here, it is the number of advantageous cards (from decks C and D) selected out of the last 60 cards, reflecting the quality of decision making under uncertainty.