Roger Dunn

Determinants of pigeons’ choice between certain and probabilistic outcomes

Pigeons chose between 50% and 100% reinforcement on a discrete-trials concurrent-chains procedure with fixed-ratio 1 initial links and fixed-time terminal links. The 100% alternative always provided food after a terminal-link delay, whereas the 50% alternative provided food or blackout equally often after a delay. Additionally, the terminal-link stimuli on the 50% alternative were correlated with the outcomes in signaled, but not in unsignaled, conditions. The effects of intertrial-interval duration and length of the terminal-link delays on choice of the 50% alternative were investigated in four experiments. Preference for the 50% alternative varied with signal condition and duration of the terminal link leading to food, but not with duration of either intertrial interval or the terminal link leading to a blackout. The results are discussed in terms of conditioned-reinforcement effects, Mazur’s hyperbolic-decay model, and delay reduction. This research was supported by a Natural Sciences and Engineering Research Council of Canada research grant awarded to the first author.

When good news leads to bad choices

Pigeons and other animals sometimes deviate from optimal choice behavior when given informative signals for delayed outcomes. For example, when pigeons are given a choice between an alternative that always leads to food after a delay and an alternative that leads to food only half of the time after a delay, preference changes dramatically depending on whether the stimuli during the delays are correlated with (signal) the outcomes or not. With signaled outcomes, pigeons show a much greater preference for the suboptimal alternative than with unsignaled outcomes. Key variables and research findings related to this phenomenon are reviewed, including the effects of durations of the choice and delay periods, probability of reinforcement, and gaps in the signal. We interpret the available evidence as reflecting a preference induced by signals for good news in a context of uncertainty. Other explanations are briefly summarized and compared.

When good pigeons make bad decisions: Choice with probabilistic delays and outcomes

Pigeons chose between an (optimal) alternative that sometimes provided food after a 10-s delay and other times after a 40-s delay and another (suboptimal) alternative that sometimes provided food after 10 s but other times no food after 40 s. When outcomes were not signaled during the delays, pigeons strongly preferred the optimal alternative. When outcomes were signaled, choices of the suboptimal alternative increased and most pigeons preferred the alternative that provided no food after the long delay despite the cost in terms of obtained food. The pattern of results was similar whether the short delays occurred on 25% or 50% of the trials. Shortening the 40-s delay to food sharply reduced suboptimal choices, but shortening the delay to no food had little effect. The results suggest that a signaled delay to no food does not punish responding in probabilistic choice procedures. The findings are discussed in terms of conditioned reinforcement by signals for good news.

College Education and Motherhood as Components of Self-concept: Discrepancies between Implicit and Explicit Assessments

Three studies examined the explicit and implicit self-concepts of college women. Participants completed self-report measures and implicit association tests measuring identification with the concepts “college education” and “motherhood.” Explicitly, participants identified more with college education than with motherhood. Implicitly, however, participants identified more with motherhood than with college education. The dissociation between mean levels of explicit and implicit identifications was more pronounced for students without children than for mothers (Study 2). In line with principles of affective – cognitive consistencies, the more motherhood was linked to the self, the stronger the correlation between attitude toward motherhood and self-esteem (Study 3). The findings show a clear discrepancy between explicit and implicit self-knowledge and reveal that motherhood plays a more important role in the self-concept of undergraduate women than self-reports would suggest.

Influence of motherhood on the implicit academic self-concept of female college students : Distinct effects of subtle exposure to cues and directed thinking

Despite notable steps toward gender equality and significant changes in gender roles, women continue to face tension between academic aspirations and the more traditional role of caregiver. The goal of the present research was to examine how this conflict might be revealed through assessments of associations that cannot be consciously controlled. In two experiments, college women completed implicit association tasks measuring the strength of their academic identification. Experiment 1 (N=55) showed that implicit academic identification was weaker when motherhood cues were present (rather than absent). In Experiment 2 (N=73), implicit academic identification was weaker when participants reflected on their aspirations to become a college graduate rather than aspirations to be a mother. These findings emphasize the malleability of the implicit academic self-concept. More precisely, they document that subtle exposure to cues and more deliberate thought processes produce distinct effects. This research contributes to a better understanding of contextual influences on the academic self-concept of college women and their potential implications for academic performances.RésuméEn dépit des progrès au niveau de l’égalité entre hommes et femmes et de changements importants dans les rôles sexuels, les femmes continuent à faire l’expérience d’un conflit entre leurs aspirations académiques et le rôle plus traditionnel de parent. Cette recherche examine dans quelle mesure ce conflit peut être révélé à l’aide de techniques mesurant des associations qui ne peuvent pas être consciemment contrôlées. Dans deux expériences, des étudiantes universitaires complétèrent des tâches d’associations implicites mesurant l’intensité de leur identification au domaine académique. L’expérience 1 (N=55) montre que l’identification académique était plus faible quand les étudiantes étaient exposées à des images évoquant le rôle de mère (que quand elles ne l’étaient pas). Dans l’expérience 2 (N=73), l’identification académique était plus faible quand les étudiantes étaient amenées à réfléchir à leurs aspirations académiques (plutôt qu’à leurs aspirations familiales). Ces résultats soulignent la malléabilité de l’identification académique implicite. Plus précisément, ils révèlent qu’être exposé de manière subtile à certaines représentations du rôle de mère ou y réfléchir consciemment produisent des effets distincts. Cette recherche contribue à mieux cerner les effets des contextes sociaux sur le concept de soi des étudiantes et leurs conséquences potentielles sur les performances académiques.

Implicit Orientation Toward Family and School Among Bilingual Latino College Students

The authors examined the associations that underlie the orientations of bilingual Latino college students toward family and school. Participants completed, in English or Spanish, 3 implicit association tests assessing their attitude toward family vs. school, identifications with these concepts, and self-esteem. Results revealed a more positive attitude toward, and stronger identification with, family than school. Identification with family was stronger among participants who completed the study in English, suggesting self-definition in terms of distinctions from the context. Last, the more participants valued family over school and identified with family rather than school, the higher was their selfesteem. These findings shed light on the subtle, yet crucial, mechanisms by which cultural knowledge is incorporated in the self-concept of bilingual Latino college students.

Mixed Aspirations: Distinctions and Relationships Between the Implicit and Explicit Self-Concepts of College Women

A sample of 128 undergraduate women reported stronger identification with college education than with motherhood. In contrast, an implicit association test revealed a slightly stronger identification with motherhood than with college education. Implicit attitudes toward college education and motherhood correlated with implicit (but not explicit) identification, whereas explicit attitudes correlated with explicit identification and, to a lesser extent, implicit identification. Internal (but not external) motivation to define the self as academically oriented predicted both explicit and implicit identifications. Results regarding the role of childhood and current experiences with gender roles were inconclusive. As a whole, these findings contribute to a better understanding of the potential for conflicts in the self-concept of college women.