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BMI and Self-Rated Attractiveness

July 19, 2011 5 comments

Frederick et.al. (2006), utilizing survey data primarily from readers at msnbc.com found a clear relationship (plotted in the image to the right) between BMI and body satisfaction. In this study, women tended to feel best about their bodies when their BMI was between 17.5-20 and men tended to feel best when their BMI was around 23-24. Using the standard rules-of-thumb for categorizing BMI values, women prefer being slightly underweight to on the low-side of normal weight. Men, on the other hand, prefer being at the higher end of normal weight. While no single illustration can accurately depict BMI (a range of heights/weights/ body types can produce identical BMI scores), the following images (available from BMI-Club) might be helpful.

Optimal BMI range for women’s self-rated body satisfaction (above).

Optimal BMI range for men’s self-rated body satisfaction (above).

Approximation of the point at which each sex’s BMI score predictably results in a “My body is unattractive” self-evaluation (above).

Approximation of the non-optimal BMI level for both women’s and men’s self-rated body satisfaction (above).

Noteworthy observations:

  • men are more satisfied with larger BMI scores (not surprising)
  • optimal BMI scores for both sexes do not predictably produce an “I have a good body” self-evaluation in either sex

Cautions

Conclusions based on the data used in this study may not generalize well to the larger population.

  • web surveys are limited by demographic differences in access to and use of the internet, sampling frame problems, response rate problems, (for external validity) and controlling access (for internal validity) (see Wiersma for a brief, accessible introduction or, e.g., DOI 10.1108/10662240510590360
  • MSNBC.com is the most popular news site on the web; the age-distribution of web news consumers is improving, but is still skewed toward the young and the educated, sex differences exist in preferences for what types of news are pursued, partisan political/ideological differences result in use of different news sources; etc. (Pew Research Center Report)
  • a recent review comparing self-report with objective measures of height and weight found a trend of under-reporting for weight and over-reporting for height in self-reports; with significant levels of variation between studies and widely divergent methods of measuring or estimating height/weight (doi: 10.1111/j.1467-789X.2007.00347.x)
  • for women the mean BMI in this study is 24.2 while the mean self-reported BMI in the NHANES study is 27.2 (and the mean measured BMI in the same study is 28.0)
  • for men the mean BMI in this study is 26.6 while the mean self-reported BMI in the NHANES study is 27.6 (and the measured BMI in the same study is 28.0)

Wayne Hooke

ResearchBlogging.org
FREDERICK, D., PEPLAU, L., & LEVER, J. (2006). The swimsuit issue: Correlates of body image in a sample of 52,677 heterosexual adults Body Image, 3 (4), 413-419 DOI: 10.1016/j.bodyim.2006.08.002

Candidate Appearance Matters

June 13, 2010 3 comments

Appearance matters – but not in the same way for male and female political candidates. Limiting this discussion to the beauty-relevant elements of Chiao, Bowman, & Gill’s 2008 study, being attractive has an effect on rates of voting for female candidates while appearing approachable has an effect on women’s rates of voting for male candidates (in a laboratory simulation). It is important to note that no other information about each candidate was given to the laboratory rater/voters.

Since the photographs were of actual candidates in U.S. Congressional elections, the authors were able to also assess how ratings of attractiveness and approachability of faces in photographs in the lab related to real-world election results. Using this metric, female candidates’ attractiveness had a much smaller effect overall (r=.09*); as did male candidates’ approachability for women (r=.18*). Appearance does seem to matter for political candidates, but, appearance is not the only thing voters attend to when voting.

Strengths

  • Stimuli were of actual political candidates

Limitations

  • Subjects were undergraduate students at Northwestern University

Interestingly, in the actual congressional elections, laboratory ratings of how competent and dominant faces appeared correlated with a candidate getting elected.

Wayne Hooke
*not statistically significant



ResearchBlogging.orgChiao, J., Bowman, N., & Gill, H. (2008). The Political Gender Gap: Gender Bias in Facial Inferences that Predict Voting Behavior PLoS ONE, 3 (10) DOI: 10.1371/journal.pone.0003666


Looking Older

April 25, 2010 1 comment

Gunn et.al. (2009), comparing a number of aged/aging twinned and non-twinned subjects (some of the non-twins were of different ages), have concluded that the primary indicators of aging in women are:

  • skin wrinkling
  • hair graying
  • lip height (measured from the “vermillion border on the philtral crest” (the high points of the upper lips spaced around the philtral groove [below the center of the nose]) to the lowest point on the lower lip – in this case, adjusted for face height due to the use of non-standard distances from face-to-camera in the making of the stimulus photos

These differences are visible in the composite photos below.

Some additional indicators of age are:

  • thinning hair
  • uneven skin tone/pigmented spotting
  • more prominent nasolabial folds (the creases that run from the corners of the nose to the corners of the mouth – primarily resulting from changes in fat deposition associated with aging)
  • possibly: receding hair

Interestingly, heritability analyses of this data indicate that signs of aging in skin are influenced equally by genetic and environmental differences; that lip height, hair graying and recession are primarily influenced by genetic factors; and that hair thinning was influenced primarily by environmental factors.

All-in-all, an interesting study and a solid contribution to the literature on aging with some implications for the psychology of beauty.

Limitations:

  • Subjects are all caucasian/northern european

Wayne Hooke



ResearchBlogging.orgGunn, D., Rexbye, H., Griffiths, C., Murray, P., Fereday, A., Catt, S., Tomlin, C., Strongitharm, B., Perrett, D., Catt, M., Mayes, A., Messenger, A., Green, M., van der Ouderaa, F., Vaupel, J., & Christensen, K. (2009). Why Some Women Look Young for Their Age PLoS ONE, 4 (12) DOI: 10.1371/journal.pone.0008021

The Good Jeans Hypothesis

February 21, 2010 Leave a comment

Just about every article I read on women’s preferences for sexual dimorphism in men points out that the data are consistent with the good genes hypothesis. There are a couple of technical variations of this hypothesis, but they all are based on the reasonably well-established connection between testosterone and impeded immune system functioning. The idea is: testosterone interferes with immunity so males who display increased phenotypic influences of testosterone must have better genes, in order to combat the toxic effects of the hormone on the immune system. So far, so good. The hypothesis is perfectly reasonable: however, it is far from substantiated. A central issue for me involves the notion of trade-offs: it is possible that the larger muscles and increased status-seeking that are associated with testosterone might result in higher status which could produce adaptive benefits, e.g., increased access to food which, at least theoretically, could compensate for the correlated decrease in immune functioning. I am not arguing that this has been shown – but I am emphasizing the hypothetical nature of the good genes hypothesis.

Regardless of the veracity of the good genes hypothesis, the beauty literature is lacking in proximal explanations for women’s increased interest (during ovulation) in sexually dimorphic features in men. Broadly speaking, the evidence continues to build that women find moderately increased levels of sexual dimorphism in males more attractive during fertile periods than during non-fertile periods (e.g., Johnston et.al, 2001). The question is, why?

My hypothesis is that ovulating women have higher levels of libido (to use the vernacular, they are a little hornier) and, when hornier, are more likely to prefer males who look like virile, competent, enthusiastic – good – lovers. Evidence is accruing that women have increased interest in sex during/around ovulation (e.g., Wilcox, et.al. 2004; Tarin & Gomez-Piquer, 2002). I also believe there is some evidence to support the assertion that the increased attraction to sexually dimorphic characteristics around ovulation could be due to the belief that such features signal competence as a lover rather than an attraction to increased masculinity per se.

For example, the above figure (Johnston, et.al. 2001) shows how women attributed personality characteristics to a face that morphed through various levels of masculinization (below).

Using frame numbers in the quick time movie (the format the morphed faces were presented in): the average attractive male face was depicted in frame 284 (below middle). When peri-ovulatory, women found frame 245 (below right) the most attractive.

This shift in preference is a shift toward both increased sexual dimorphism and to the perception of increased competence as a lover. Since the average optimally attractive male face (frame 245) more closely approximates the face that looks like the optimal lover (approximately: frame 190) rather than the one identified as masculine (frame 115), it seems prudent to consider the possibility that peri-ovulatory shifts in attractiveness ratings might result from an increased interest in the perceived sexual characteristics of the depicted male rather than in his masculinity per se.

Wayne Hooke

Blue Jeans photo courtesy of Hendrike, 2005.  Wikipedia Commons.

ResearchBlogging.orgJohnston, V. (2001). Male facial attractiveness: evidence for hormone-mediated adaptive design Evolution and Human Behavior, 22 (4), 251-267 DOI: 10.1016/S1090-5138(01)00066-6

Tarin, J. (2002). Do women have a hidden heat period? Human Reproduction, 17 (9), 2243-2248 DOI: 10.1093/humrep/17.9.2243

Wilcox, A. (2004). On the frequency of intercourse around ovulation: evidence for biological influences Human Reproduction, 19 (7), 1539-1543 DOI: 10.1093/humrep/deh305

ROMANTIC REDux

February 17, 2010 2 comments

About two years ago, Elliot & Niesta (2008), concluded that the color red makes men find women more attractive. Essentially, they found that men – but not women – rated black and white photos of women about a point higher in physical attractiveness (on a 9-point scale) when the photos were presented on a red background than when presented on a white/gray/green background. They also found a similar result when the woman’s shirt was red rather than blue in a color photograph. The authors favor a sexual-signalling interpretation of these results: that men key into displays of red in women due to the color’s role in signaling sexual health/availability/interest/arousal (they do acknowledge, however, that other – more culturally influenced – explanations for this data are possible). The implication is that red enhances attractiveness (the photos used reasonably attractive subjects) – not by an intrinsic characteristic of the stimulus like symmetry or averageness – but by somehow covertly activating sexual cognition in men. I have been unable to find a replication of this research in the subsequent literature. After two years, this lack of replication or direct follow-up on a variable with this much potential impact on attractiveness ratings is concerning.

I am aware of one subsequent study that relates the color red to attractiveness indirectly: Stephen, et.al. (2009) have found that the color “blood red” makes faces appear healthier (apparently, no direct rating of attractiveness was used in this study). Other psychology of color studies have been and continue to be published: with no clear application to beauty research. For example, using a Stroop-like methodology, Moller et.al. (2009) found that the color red is implicitly associated with failure and negativity – a relationship that is difficult to mesh with the Elliot & Niesta data.

The photo of Daniela Niesta (below) is available from the University of Rochester website:

It is possible to download a full-size version of the image from this page. If you do, I urge you to look at the images displayed in this photo. They are examples of the stimuli used in experiment five. To my eye, on my color calibrated monitor, the skin tone in the image with the red shirt is more pleasing. This is likely due to a contrast effect, as only the colors of the shirt were manipulated by the experimenters. This, of course, suggests a competing explanation for the data (at least of experiment five).

All-in-all, a cautious acknowledgment of the conclusions reached in the Elliot & Niesta study is called for, pending replication and clarification in further research.

Wayne Hooke

Photo of J.W.Waterhouse’s Lady of Shalott courtesy of Wikipedia Commons.

Photo of Daniela Niesta courtesy of the University of Rochester.

ResearchBlogging.orgElliot, A., & Niesta, D. (2008). Romantic red: Red enhances men’s attraction to women. Journal of Personality and Social Psychology, 95 (5), 1150-1164 DOI: 10.1037/0022-3514.95.5.1150

Moller, A., Elliot, A., & Maier, M. (2009). Basic hue-meaning associations. Emotion, 9 (6), 898-902 DOI: 10.1037/a0017811

Stephen, I., Coetzee, V., Law Smith, M., & Perrett, D. (2009). Skin Blood Perfusion and Oxygenation Colour Affect Perceived Human Health PLoS ONE, 4 (4) DOI: 10.1371/journal.pone.0005083

Testosterone is Not a Handicap

February 3, 2010 1 comment

Many contemporary beauty researchers assume/conclude that attractive, sexually dimorphic features in men (strong jaws, increased lean muscle mass, etc.) are true signals of mate quality. This model is best illustrated in peacock tail feathers: the size and color of the train makes the male more sexually attractive to peahens. Rather than being just an attractive, but functionally useless ornament, this weighty handicap is an honest signal to peahens of the male’s quality – because this tail is so costly to possess. Any peacock that can thrive with this large disadvantage must be well-adapted – that is, possess good genes.

Testosterone inhibits immune functioning. Given this, the basic argument is that any potential mate with testosterone-related features must have “good genes” in order to thrive with the testosterone handicap. One big problem with the testosterone as a handicap hypothesis is that testosterone is not merely an immunity suppressant. Testosterone produces benefits as well:

The primary fitness benefits of testosterone are multifaceted, including support for optimal spermatogenesis, the development and maintenance of secondary sexual characteristics that augment male competitiveness and attractiveness, as well as libido. Other associations include competitive ability and possible relationships with social dominance. (Bribiescas & Ellison, p. 104)

Thus, testosterone’s effects involve trade-offs: there are pros and cons to having testosterone coursing through one’s veins.

The second big problem with this hypothesis is that there is no evidence for this phenomenon in mammals. Roberts, et.al. (2004) found evidence for the immunocompetence handicap hypothesis (what I am calling the testosterone as handicap hypothesis) in birds and reptiles, but not mammals. Nunn, et.al. (2008) subsequently corroborated this conclusion with regard to mammals.

Arguments which assume sexually attractive, dimorphic features in human males are costly handicaps – and thus true signals – are overlooking the complex influence of testosterone in human adaptations as well as overlooking the lack of evidence for applying this concept to mammals generally and humans specifically.

Wayne Hooke

Image courtesy of Rhodney Carter, Wikipedia Commons.


ResearchBlogging.orgRichard G. Bribiescas & Peter T. Ellison (2008). How hormones mediate trade-offs in human health and disease. (77-94). Evolution in Health and Disease, Stearns & Koella (eds.).

Nunn, C., Lindenfors, P., Pursall, E., & Rolff, J. (2009). On sexual dimorphism in immune function Philosophical Transactions of the Royal Society B: Biological Sciences, 364 (1513), 61-69 DOI: 10.1098/rstb.2008.0148

ROBERTS, M., BUCHANAN, K.L., & EVANS, M.R. (2004). Testing the immunocompetence handicap hypothesis: a review of the evidence Animal Behaviour, 68 (2), 227-239 DOI: 10.1016/j.anbehav.2004.05.001

Sexual Orientation, Sociosexuality, and Sexual Dimorphism

January 16, 2010 Leave a comment

Using digitally manipulated levels of sexual dimorphism in human male and female faces (like the ones to the right), Glassenberg et.al. (2009) found that, compared to heterosexual women, homosexual women preferred greater masculinization in female faces [Brown-Forsythe t(303.38) = -2.92, p<.01] while heterosexual women preferred greater masculinization in male faces [t(375) = 6.77, p<.001]. Compared to heterosexual males, homosexual males preferred masculinization in both male and female faces [t(520) = -7.42, p<.001 and t(520) = -6.72, p<.001 respectively]. Calculations based on sociosexual orientation were mostly non-significant, though relatively small, significant, positive correlations were found in heterosexual males between unrestricted SO and a preference for feminization in female faces [R(125) = .20, p<.05] while homosexual males showed a positive correlation between unrestricted SO and a preference for masculinized male faces [R(259) = .17, p<.001]. These specifics aside, all raters preferred feminized female faces to masculinized female faces.

Strengths

  • large sample

Concerns

  • rated stimuli consisted of 3 face composites to ensure recognizable individuality. There was no effort to match stimuli for attractiveness prior to manipulating sexual dimorphism, so an attractiveness x dimorphism interaction would be missed in this design.

This study suggests that homosexuals’ preferences are neither identical to nor mirror-images of heterosexuals’ preferences. This data also suggests that researchers should control for sexual orientation when conducting attractiveness studies in which sex/gender are relevant variables.

Wayne Hooke



ResearchBlogging.orgGlassenberg, A., Feinberg, D., Jones, B., Little, A., & DeBruine, L. (2009). Sex-Dimorphic Face Shape Preference in Heterosexual and Homosexual Men and Women Archives of Sexual Behavior DOI: 10.1007/s10508-009-9559-6

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