Trustworthiness perception is mandatory: Task instructions do not modulate fast periodic visual stimulation trustworthiness responses

Abstract

Although it is often assumed that humans spontaneously respond to the trustworthiness of others’ faces, it is still unclear whether responses to facial trust are mandatory or can be modulated by instructions. Considerable scientific interest lies in understanding whether trust processing is mandatory, given the societal consequences of biased trusting behavior. We tested whether neural responses indexing trustworthiness discrimination depended on whether the task involved focusing on facial trustworthiness or not, using a fast periodic visual stimulation electroencephalography oddball paradigm with a neural marker of trustworthiness discrimination at 1 Hz. Participants judged faces on size without any reference to trust, explicitly formed impressions of facial trust, or were given a financial lending context that primed trust, without explicit trust judgement instructions. Significant trustworthiness discrimination responses at 1 Hz were found in all three conditions, demonstrating the robust nature of trustworthiness discrimination at the neural level. Moreover, no effect of task instruction was observed, with Bayesian analyses providing moderate to decisive evidence that task instruction did not affect trustworthiness discrimination. Our finding that visual trustworthiness discrimination is mandatory points to the remarkable spontaneity of trustworthiness processing, providing clues regarding why these often unreliable impressions are ubiquitous.

First impressions from faces in dynamic approach–avoidance contexts.

“…This is in line with the evidence that such judgments occur quite rapidly, although with limited validity (Foo et al, 2022; Todorov, 2017; Todorov et al, 2015; Willis & Todorov, 2006). It is also consistent with the suggestion that these processes are at least partially automatic, due to such judgments occurring so quickly and possibly inevitably (Ritchie et al, 2017; Sutherland & Young, 2022; Swe et al, 2022).…”

A first impression of the future

“…We agree that such research is vital. Recently, the first author investigated this question by comparing electrophysiological signals measured over the visual cortex in response to trustworthy and untrustworthy faces, either during incidental viewing, while imagining playing a trust game, or while engaged in an explicit impression formation goal (Swe et al, 2022). Interestingly, Bayesian analyses found moderate to strong evidence for equally robust neural responses across the incidental and goal-directed contexts, suggesting that some aspects of processing facial appearance, at least when recorded over the visual cortex, may be relatively unaffected by explicit goals.…”