An experimental analysis of the classic overjustification effect in rats: Does the removal of “expected” rewards alter behavior in rats as it does in humans?

<p>The overjustification effect posits that rewards undermine intrinsic motivation, such that an individual’s engagement in previously intrinsically motivating tasks will decrease when a previously reliable reward is withdrawn. This study aimed to determine if this overjustification effect can be demonstrated in rats, with typical confounds related to social and verbal aspects of reward delivery controlled for. Baseline “intrinsic” wheel-running rates of seven SpragueDawley rats were compared to rates that followed administration and withdrawal of a contingent sucrose reward, and to rates of rats in control conditions (n = 7). Consistent with the author’s hypothesis, the reward group’s wheel-running did not decrease below the initial baseline following this procedure, as would be predicted by the overjustification hypothesis. This suggests that the overjustification effect demonstrated in humans may be better conceptualized as being related to social and verbal aspects of rewards rather than as an inherent feature of reward administration and withdrawal.</p>

Name thesis:degree_name

Master of Science (MS)

Level thesis:degree_level

Open Access Thesis

Discipline thesis:degree_discipline

Psychology

Year dc:date.available

2021

Author dc:creator

• Sunde, Eleah

Contributors dc:contributor

• James Todd, Ph.D.
• Rusty McIntyre, Ph.D.
• Kenneth Rusiniak, Ph.D.

• overjustification
• rats
• reinforcement
• rewards
• undermining effect
• wheel-running
• Psychology
• Social Psychology

Repository record dc:identifier

https://commons.emich.edu/theses/1086

OAI identifier oai:identifier

oai:commons.emich.edu:theses-2466