Faces and sex

Faces and sex

• Thomas R. Stewart, Ph.D.

• Center for Policy Research

• Rockefeller College of Public Affairs and Policy

• University at Albany

• State University of New York

• [e-mail]

Citation

• Lynda G. Boothroyd, Benedict C. Jones, D. Michael Burt, Lisa M. DeBruine, David I. Perret. Facial correlates of sociosexuality. Evolution and Human Behavior xx (2008, in press)

Sociosexual Orientation Inventory (SOI)

• Sociosexual Orientation Inventory (SOI) developed by Simpson and Gangestad (1991). The SOI was developed to assess individual propensity to engage in short term sexual relationships. A high score on the SOI indicates an ‘unrestricted’ sociosexuality (i.e., being more open to short-term sexual relationships) while a low score indicates a ‘restricted’ sociosexuality (i.e., being less willing to engage in short-term sexual relationships).

• (see link to the questionnaire on the wiki)

Study 1

• Study 1 used facial composites of unrestricted (open to short-term relationships) and restricted (prefer long-term relationships) individuals. The principle of averaging images means that randomly varying traits across two groups will tend towards average in composites, while traits that are significantly different between groups will be more clear in composites (Perrett et al., 1994). Thus, this method is ideal for detecting subtle structural differences between groups (e.g., a larger, squarer jaw in the case of masculine males) and for assessing whether groups of observers are sensitive to these differences. (p. 2)

Male composite pictures from the paper

Caption – male on right is composite of unrestricted males

• Fig. 1. Extended forced choice testing program as used in Sample 1b displaying the Male Batch 1 pair composite images of restricted (left) and unrestricted (right) individuals. In Sample 1a, a similar program was used with the labels next to the buttons.

Female composite pictures from the paper

Caption – Female on right is composite of unrestricted males

• Fig. 2. Female Batch 1 composites of restricted (left) and unrestricted (right) individuals.

Study 1 results

• Both male and female observers considered the unrestricted sociosexuality female composites more attractive than the more restricted female composites (males assessing longterm: mean=3.976, t20=2.63, p<.05; males assessing shortterm: mean=3.929, t20=2.50, pb.05; females assessing same sex attractiveness: mean=4.238, t20=3.49, p<.01). Female observers considered composites of restricted males to be more attractive than composites of unrestricted males for long-term relationships (mean=2.952, t20=2.20, p<.05) but showed no significant preference for short-term relationships (t20=0.55). Male observers had no preference either between unrestricted and restricted male composites (t20=0.04). (p. 4)

Study 2

• … despite the advantages of composites, as discussed in Study 1 above, one might argue that composites are too controlled when considering behavioural attributions and that observers must be able to detect differences in real faces if we are to claim that they are capable of differentiating between social partners in reality. Therefore, Study 2 was conducted using real individual faces rather than composites. (p. 5)

Study 2 effect sizes (underlining added)

• There were significant positive correlations between all perceived restrictedness (i.e., apparent SOI) ratings and all components of the SOI scores of the photographed individuals (all rs>0.27, all p<.07, two-tailed), with the exception of reported and rated number of sexual partners within the last year, neither of which correlated with any other measure (all p<.25). Furthermore, individuals' full SOI scores were significantly correlated with the mean rated SOI across all four questions (rs=0.367, p<.05). The correlation between SOI score and mean perceived SOI remained significant after controlling for individual's age and sex, same-sex ratings of attractiveness, and masculinity/femininity. Furthermore, results remained significant when male and female observers' judgments were analysed separately. There was a trend for higher SOI to be associated with greater perceived femininity in female faces (rs=0.399, p=.098, n=23) but no further significant correlations. (p 5)

Judging sexual strategy from faces - Summary http://www.boothlab.org/

• A research paper currently published in Evolution and Human Behavior shows that we may be subtly aware of other people’s attitudes to sex. Three groups of undergraduate students were photographed and completed a questionnaire called the sociosexual orientation inventory (SOI) which asks about past sexual behaviour (e.g. number of one night stands) and current attitudes – such as "is sex without love okay"? Observers were then shown either real individuals faces or ‘average’ images of faces, and it seemed that across the studies, observers were often able to distinguish between those who scored low on the SOI (and thus are not generally keen on casual sex) and those with high scores (who tend to have had more partners and be more comfortable with uncommitted sex). However, what is far more interesting, is that despite the subtlety of the explicit awareness of who-thinks/does-what, there is a very strong tendency for women to be attracted to men who score low on the SOI – i.e. men who are less interested in casual sex. Men have the opposite preference with female faces; they strongly prefer the ‘high SOI’ women. In fact, even other women thought that high SOI females were more attractive. Furthermore, high SOI men were also viewed as looking more masculine. This backs up previous work which showed that more masculine men were perceived as being less likely to commit to a long term relationship; now we can see that men who are less likely to be in a long term relationship (although the questionnaire doesn’t actually ask about that) also look more masculine. These convergent lines of evidence support the idea that part of the variation in women’s preferences for male masculinity is due to the negative connotations it has for long term partnerships.

Gangestad et al. (1992) abstract

• Gangestad, S. W., J. A. Simpson, et al. (1992). "Differential accuracy in person perception across traits: Examination of a functional hypothesis." Journal of Personality and Social Psychology 62(4): 688-698.

• Although strangers can assess certain traits of unacquainted others with moderate validity, overall validity is low. Differential validity across traits may be due to (1) the extent to which targets display valid cues or (2) the extent to which perceivers validly use cues. A functionalist perspective suggests that valid cue utilization should vary with how important the consequences of accurate trait assessment are. It was predicted from this perspective that perceivers would judge strangers' sociosexuality more accurately than 3 other traits (social potency, social closeness, and stress reaction). Perceivers viewed 1-min videotaped segments of targets being interviewed and rated them on the 4 traits. Ratings were correlated with target-reported trait measures. As predicted, perceivers' ratings of male sociosexuality agreed relatively well with self-reports. This effect was moderated by sex of target and sex of perceiver.

Gangestad et al. (1992) hypothesis

Gangestad et al. (1992) lens model diagram

Gangestad et al. (1992) method

• Perceivers viewed 1-min presentations (interviews) of 20 targets in which only visual cues were available to them. They then rated each target on four traits: sociosexuality, social potency, social closeness, and stress reaction. Data were analyzed in two ways. First, we correlated raters' social judgments with self-report markers of the traits provided by targets. Second, we broke overall accuracy into components specified by the lens model. To do so, we identified and measured a number of obvious cues that perceivers could potentially use. (p. 690)

Gangestad et al. (1992) advantage of lens model analysis

• Perceivers could have used cues other than those we measured (e.g., more subtle forms of nonverbal expressions not reflected in gross measures such as percentage of time smiling). Through lens model analyses, however, we were able to assess the extent to which perceivers' agreement with target self-reports were attributable to valid use of the cues we both did and did not measure. (p. 690)

Gangestad et al. (1992) (behaviors and impressions)

• All interviews were viewed by trained raters and coded for the occurrence of specific behaviors (e.g., the percentage of time spent smiling, the percentage of time eye contact with the camera was maintained) as well as 34 specific impressions the inteviewees conveyed during the interview (e.g., how animated they were, how relaxed they appeared, and how phony they appeared. (p. 691)

Gangestad et. al. results p. 693

Gangestad et. al. results p. 693 (physical attractiveness partialed out)

Gangestad et al. (1992) impression factors

• The resultant factors included:

• (a) Social Engagement (marked by high ratings on engaging, witty, competent, stimulating, disclosing, drawing attention to self, dominant, captivating, and skilled, and low ratings on dull);

• (b) Interest (marked by high ratings on flirtatious, inviting, conveys interest, and bold);

• (c) Comfort (marked by high ratings on relaxed and low ratings on anxious, self-conscious, inhibited, and shy);

• (d) Provocativeness (marked by high ratings on seductive, provocative, and sexually appealing); and

• (e) Pretentiousness (marked by high ratings on arrogant and phony, and low ratings on nice). (p. 691)

Gangestad et al. (1992) cues

• Two sorts of behavioral cues were measured. First, we assessed 11 dimensions of the targets' nonverbal behavior displayed during the presentation (e.g., percentage of time spent smiling, percentage of time maintaining eye contact, and number of laughs). Five principal components are known to account for the bulk of the variance underlying these 11 behavioral indicators. We treated these components as composite behavioral cues. Second, we assessed global impressions created by the targets during their presentations. Independent raters evaluated each target on a heterogeneous set of 34 adjective descriptors (e.g., animated, inhibited, and relaxed). Five interpretable factors underlie these descrip tors (Simpson et al., 199 l), and we treated these five dimensions as impressionistic cues.

Gangestad et. al. results p. 694 (lens model analysis)

Note on table 4

Discussion (p. 695)

• We predicted that, relative to three other prominent traits, social perceivers could validly assess the trait of sociosexuality on the basis of brief exposure to previously unacquainted individuals. Results supported our predictions. In general, social perceivers' ratings of sociosexuality corresponded with target self-reports to a greater extent than did their ratings of social potency, social closeness, and stress reaction.

• It seems reasonable to suggest that the enhanced target-perceiver agreement on sociosexuality was in fact attributable to relatively superior validity of perceivers' ratings. The obvious alternative explanation that enhanced agreement was due to relatively superior validity of target self-reports on sociosexuality seems implausible. The reliabilities of the target self-reports on social potency, social closeness, and stress reaction all exceeded the reliability of the SOI, and although reliability does not imply validity, all three trait measures have been shown to relate substantially to peer report.

• In addition to the overall superiority of perceiver ratings of sociosexuality, however, we found that perceiver-target agreement on sociosexuality was moderated by sex of target and sex of perceiver. Perceivers could assess male sociosexuality with greater accuracy than female sociosexuality Furthermore, male perceivers demonstrated superior assessment of sociosexuality relative to female perceivers.

Discussion – lens model (p. 695)

• Lens model analyses designed to identify the locus of enhanced perceiver-target agreement on sociosexuality revealed that perceiver assessments of sociosexuality were not superior because perceivers utilized cues we measured more validly (even though perceivers did utilize these cues in valid ways when assessing male targets). Rather, the superiority of perceivers' ratings of sociosexuality primarily stemmed from their utilization of cues not captured by our measures. The explicit cues we assessed were relatively gross motor ones (e.g, time spent smiling and time leaning forward). Perceivers may have utilized cues involving subtle microfacial expressions and body movements to validly assess sociosexuality