Association for Behavior Analysis International

Different experimental approaches to the study of factors that influence human choice will be presented and discussed. Avila-Chauvet et al. used an online game to study the factors that promote strategy change in social foraging situations in which members of a group must choose between searching their own food sources (Produce) or joining a previously discovered food source (Scrounge). Jimenez-Lozano et al. tested introducing a discriminative stimulus that signaled the value of the consequences on the sunk-cost effect - i.e., persistence in an endeavor once an investment has been made, even when a better option is available. Hurtado-Parrado et al. used a choice task that delivered points exchangeable for money to test the effects of presenting non-contingent visual aversive stimulation (images from the International Affective Picture System – IAPS) on self-controlled behavior - i.e., choice of a large delayed reinforcer over the choice of a small immediate reinforcer (choosing 10 points after a delay of 16 s over 2 points after 4 s).

The sunk cost effect is the tendency to persist in an endeavor once an investment has been made even when a better option is available. Studies using a sunk cost experimental model have demonstrated that the effect disappears in pigeons when Discriminative Stimuli (DS) signal the value of the consequences. In humans, the DS decrease the effect but do not eliminate it. In two experiments, the role that DS might have on the sunk cost effect in humans was evaluated. In Experiment 1, to evaluate the sunk cost effect in the presence and absence of DS, Navarro and Fantino’s (2007) procedure was replicated. Unlike the original study, results showed no influence of the DS on the sunk cost effect. In Experiment 2, differential responding to the DS was assessed along with the relationship between stimuli discrimination and responding persistence in the presence of DS. The discrimination index of participants with lower percentages of persistence (Escapers) was significantly higher (p = 0,028) than to participants with higher percentages (Persisters). Results suggest that discriminating the stimuli associated with changes in the reinforcement contingency decreases the sunk cost effect.

In social foraging situations the members of a group have to choose between searching their own food sources (Produce) or joining a previously discovered food source (Scrounge). We evaluated the strategy changes (Produce/Scrounge) using an online game that simulates an animal social foraging situation. We expose eighty undergraduate students to different conditions manipulating group size and number of preys in the patch zones. The results regarding the proportion of producer tactics are qualitatively similar to those reported in animals: as the size of the group increases the proportion of producers within the group tend to decrease. On other hand, two of the factors that promote strategy change are the distance between agents and the effectiveness of others. It is discussed that animals and humans share similar mechanisms in choice strategy in social foraging settings

Flora and Schieferecke (1992) demonstrated that non-contingent aversive noise increased impulsive responses during a choice task. Participants pressed buttons for money-exchangeable points. Impulsive choice produced 2 points over a 4-s delay. Self-controlled choice produced 10 points after a 16-s delay. Flora et al. (2003) replicated this effect when, concurrently to the choice task, participants earned extra points by immersing a hand in cold water. We (a) tested the generality of the impulsivity effect with non-painful stimulation – aversive images from the International Affective Picture System – IAPS (Bradley & Lang, 2007); and (b) assessed if emotional arousal, whether positive or negative, was responsible for the impulsivity effect. During interspersed trials added to Flora et al.’s task, participants (88 Male; 115 Female college students) searched for a stimulus hidden in aversive, appetitive, or neutral images, and earned 5 points for each correct match. Clear preference for the self-controlled option was observed in the control condition (no images), same as Flora et al. reported. Images, irrespective of their emotional valence, significantly increased impulsive responses. Men were more impulsive than women when exposed to aversive images. Aversive state produced by impossibility to find the hidden stimulus could explain the observed effects.