A map of decoy influence in human multialternative choice

TY - JOUR

T1 - A map of decoy influence in human multialternative choice

AU - Dumbalska, Tsvetomira

AU - Li, Vickie

AU - Tsetsos, Konstantinos

AU - Summerfield, Christopher

N1 - Copyright © 2020 the Author(s). Published by PNAS.

PY - 2020/10/6

Y1 - 2020/10/6

N2 - Human decisions can be biased by irrelevant information. For example, choices between two preferred alternatives can be swayed by a third option that is inferior or unavailable. Previous work has identified three classic biases, known as the attraction, similarity, and compromise effects, which arise during choices between economic alternatives defined by two attributes. However, the reliability, interrelationship, and computational origin of these three biases have been controversial. Here, a large cohort of human participants made incentive-compatible choices among assets that varied in price and quality. Instead of focusing on the three classic effects, we sampled decoy stimuli exhaustively across bidimensional multiattribute space and constructed a full map of decoy influence on choices between two otherwise preferred target items. Our analysis reveals that the decoy influence map is highly structured even beyond the three classic biases. We identify a very simple model that can fully reproduce the decoy influence map and capture its variability in individual participants. This model reveals that the three decoy effects are not distinct phenomena but are all special cases of a more general principle, by which attribute values are repulsed away from the context provided by rival options. The model helps us understand why the biases are typically correlated across participants and allows us to validate a prediction about their interrelationship. This work helps to clarify the origin of three of the most widely studied biases in human decision-making.

AB - Human decisions can be biased by irrelevant information. For example, choices between two preferred alternatives can be swayed by a third option that is inferior or unavailable. Previous work has identified three classic biases, known as the attraction, similarity, and compromise effects, which arise during choices between economic alternatives defined by two attributes. However, the reliability, interrelationship, and computational origin of these three biases have been controversial. Here, a large cohort of human participants made incentive-compatible choices among assets that varied in price and quality. Instead of focusing on the three classic effects, we sampled decoy stimuli exhaustively across bidimensional multiattribute space and constructed a full map of decoy influence on choices between two otherwise preferred target items. Our analysis reveals that the decoy influence map is highly structured even beyond the three classic biases. We identify a very simple model that can fully reproduce the decoy influence map and capture its variability in individual participants. This model reveals that the three decoy effects are not distinct phenomena but are all special cases of a more general principle, by which attribute values are repulsed away from the context provided by rival options. The model helps us understand why the biases are typically correlated across participants and allows us to validate a prediction about their interrelationship. This work helps to clarify the origin of three of the most widely studied biases in human decision-making.

KW - Choice Behavior/physiology

KW - Commerce/economics

KW - Decision Making/physiology

KW - Female

KW - Humans

KW - Male

KW - Motivation/physiology

UR - https://doi.org/10.1073/pnas.2005058117

U2 - 10.1073/pnas.2005058117

DO - 10.1073/pnas.2005058117

M3 - SCORING: Journal article

C2 - 32958673

VL - 117

SP - 25169

EP - 25178

JO - P NATL ACAD SCI USA

JF - P NATL ACAD SCI USA

SN - 0027-8424

IS - 40

ER -