Motivational drivers for serial position effects: Evidence from high-stakes legal decisions

Area of Science:

• Legal Psychology
• Behavioral Economics
• Decision Science

Background:

• Serial position effects are common in sequential decision-making across various professions.
• Existing explanations often attribute these effects to decision-maker fatigue.
• However, serial position effects persist even when fatigue is unlikely, suggesting alternative mechanisms.

Purpose of the Study:

• To investigate the role of motivational factors, specifically the desire for consistency, in driving serial position effects in decision-making.
• To differentiate between fatigue-based and motivation-based explanations for serial position effects.
• To examine these effects in high-stakes legal decision-making contexts.

Main Methods:

• Analysis of two large-scale field data sets: U.S. immigration judges' asylum decisions (N=386,109) and 18th-century London criminal court jury decisions (N=20,796).
• Distinguishing and testing predictions from five distinct mechanisms driving serial position effects.
• Examining the persistence of effects over breaks and the influence of decision-maker experience.

Main Results:

• Decisions showed a trend toward increased leniency as a function of serial position, supporting motivation-based explanations over fatigue-based ones.
• This leniency effect persisted even after breaks in the decision-making sequence.
• The leniency effect was more pronounced among more experienced decision-makers, aligning with motivational accounts.

Conclusions:

• Serial position effects in decision-making can be significantly driven by a motivation to maintain consistency, rather than solely by fatigue.
• Understanding these motivational drivers is crucial for explaining the prevalence and persistence of serial position effects.
• This research offers insights into reducing unwanted serial position effects in sequential decision-making processes.