Facial attractiveness impressions precede trustworthiness inferences: lower detection thresholds and faster decision latencies

ABSTRACT

Prior research has found a relationship between perceived facial attractiveness and perceived personal trustworthiness. We examined the time course of attractiveness relative to trustworthiness evaluation of emotional and neutral faces. This served to explore whether attractiveness might be used as an easily accessible cue and a quick shortcut for judging trustworthiness. Detection thresholds and judgment latencies as a function of expressive intensity were measured. Significant correlations between attractiveness and trustworthiness consistently held for six emotional expressions at four intensities, and neutral faces. Importantly, perceived attractiveness preceded perceived trustworthiness, with lower detection thresholds and shorter decision latencies. This reveals a time course advantage for attractiveness, and suggests that earlier attractiveness impressions could bias trustworthiness inferences. A heuristic cognitive mechanism is hypothesised to ease processing demands by relying on simple and observable clues (attractiveness) as a substitute for more complex and not easily accessible information (trustworthiness).

KEYWORDS:

• Trustworthiness
• attractiveness
• time course
• facial expression
• expressive intensity

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

David Beltrán http://orcid.org/0000-0003-1658-5915

Manuel G. Calvo http://orcid.org/0000-0003-1083-9929

Notes

1. We assessed subjective perception of trustworthiness (and attractiveness) rather than actual trust behavior. Prior studies have, nevertheless, demonstrated that trustworthiness judgments are related to measures of behavioural approach or avoidance (Centorrino et al., 2015; Krumhuber et al., 2007).

2. An issue for further research involves the orthogonal manipulation of trustworthiness and attractiveness, to separate their effects. In the current study and in prior research, these dimensions were naturally highly related (at least for young-adult real faces). A possible way of disentangling their effects could involve manipulating age. By means of this approach, we could create faces that are trustworthy but not attractive (as age is often trustworthy but seldom attractive), or vice versa.

3. Facial expressions of emotion typically develop from lower to higher intensities. This implies that lower intensities occur and are available to an observer earlier than higher intensities. In our study, the lower-intensity stimuli corresponded to an earlier unfolding stage from a neutral to a full-blown emotional expression, relative to higher intensities developing later. Thus, sensitivity to attractiveness at lower intensities (relative to trustworthiness) means that a given expression provides enough clues to detect un/attractiveness before they allow for un/trustworthiness detection, which needs additional expressive unfolding, at a later stage.

4. There is a well-known attractiveness halo effect (or beauty-is-good stereotype) whereby physically attractive individuals are believed to possess a variety of desirable personal qualities. We have argued that an earlier facial un/attractiveness impression might influence a later un/trustworthiness inference. Whether this mechanism is domain-general (for other personal traits, such as friendliness, intelligence, etc.) or specific for trustworthiness is currently unknown.

5. Dominance is another major dimension involved in facial first impressions (see Sutherland et al., 2017). Modelling studies have shown a clear separation between dominance and trustworthiness (Oosterhof & Todorov, 2008) and also—to a lesser extent—between dominance and attractiveness (Oosterhof & Todorov, 2008; Vernon, Sutherland, Young, & Hartley, 2014). It is thus unlikely that the attractiveness/trustworthiness relationship in the current study is confounded with dominance.

Additional information

Funding

This study was supported by the Spanish Ministerio de Economía y Competitividad, Secretaría de Estado de Investigación, Desarrollo e Innovación under Grant PSI2014-54720-P, awarded to Manuel G. Calvo.