Computational and motivational mechanisms of human social decision making involving close others

Abstract

Every day, human beings make decisions with social consequences. These social consequences matter most when they impact those closest to us. Recent research has shown that humans exhibit reliable preferences when deciding between conflicting outcomes involving close others-for example, prioritizing the interests of one's family member over one's friend. However, virtually nothing is known about the mechanisms that drive these preferences. We conducted a pre-registered study in a large (maximum N =375) sample to quantify the computational and motivational mechanisms of human social decision-making preferences involving close others. By pairing assessment techniques from behavioral economics and psychological science with computational modeling and random coefficient regression, we show that valuebased cognitive computations (e.g., risk and loss aversion) drive social decisionmaking preferences involving financial outcomes, whereas socioemotional motivations (e.g., relationship quality) underlie preferences involving social outcomes. These results imply mechanistic heterogeneity, underscoring a need for greater attention to contextual specificity in social decision-making.

Social Decision Preferences for Close Others are Embedded in Neural and Linguistic Representations

“…Each run lasted approximately 90-135 s, with variability owing to the self-paced nature of the task. The visual configuration of task stimuli were generally consistent with prior implementations 22,52 . Both runs were programmed in PsychoPy 53 .…”

“…Values for each type of reward ranged from 2 -30. There were 49 unique combinations of reward and time pairings (e.g., $2 now versus $18 two weeks from now) for each condition, resulting in 294 unique possible trial types 22 . In the interest of reducing in-scan task demands for participants, each run was comprised of 30 trial types randomly selected from the total 294.…”

“…Third, examining choice preferences among individuals within the category of close others helps map behavioral tendencies in a finer-grained manner (as opposed to coarsely examining choice preferences between close versus non-close others) that is likely to capture the kinds of distinctions that pervade everyday life, where people must often consider the consequences of their choices for multiple familiar others (rather than deciding, for example, whether to favor a friend or a stranger). We specifically studied choice preferences between a parent and close friend because group-level choice preferences between parents and friends have been well documented 1,21,22 , and because these two particular relationship categories are motivationally salient across individuals and for much of the lifespan [23][24][25][26][27] .…”

Choosing for others changes dissociable computational mechanisms underpinning risky decision-making

“…It therefore stands to reason that the component processes underlying risky decision-making may be susceptible to social modulation, which has significant implications for understanding how we make value-based decisions that affect others. While there have been some differences reported across a range of ages in the general pattern of risky choices made for friends relative to others 27 , 28 and for parents relative to peers 29 , 30 , it is unclear from this work what changes in decision-making across these different contexts. Thus, we do not yet know the specific ways in social closeness does (or does not) alter the underlying computational processes supporting decision-making under risk.…”

“…Powers and colleagues 28 found increased risk aversion when considering choice options involving risky gains or losses for a friend, relative to choices only affecting themselves, suggesting a bias toward protecting close others from potential negative outcomes. Additionally, work by Guassi-Moreira and colleagues 30 reported no differences in overall levels of risk aversion and trend-level decreases in loss aversion when evaluating risky choices for parents relative to friends. Our decision to include a stranger condition, in conjunction with our unique modeling approach, allowed us to build upon these findings by mechanistically characterizing how the involvement of specific close others and strangers in choices additively shifts people’s idiosyncratic baseline risk attitudes toward risk-taking as a function of our real-life relationship with that person.…”