Friday, 2 September 2011

Width-to-height ratio of the face for family history investigations


The widely respected Dienekes' Anthropology Blog carried an article recently "Broad-faced behavioral correlates / the rise of the new physiognomics?" which caught my attention.

Two new papers look at correlations between broad faces and behavior. One indicates that broad-faced CEOs lead better performing companies; the other that wider faces might predict unethical behavior in men. Apparently width-to-height ratio of the face had been previously found to be positively linked to aggressiveness and untrustworthiness. Dienekes didn't comment on those attributes in CEOs.
I confess to being pretty skeptical about the value of this type of correlation. However, the article did remind me of a presentation I attended quite a few years ago where the speaker was trying to decide if two photographs, taken many years apart, were of the same person. As I recall the spacing of the eyes was used to show to the speaker satisfaction that they were the same person. I wasn't convinced.

I thought I'd look at the width to height ratio of the face, as defined in this diagram, on the same person at different times to see how much it varied. It turns out the measurement is sensitive to the position of the face relative to the camera. It must be centered vertically and horizontally.

In the diagram above the low-ratio face is 1.8, the high ratio 2.1, not a lot of difference. The article (pdf) from which it comes shows the ratio varying between 1.5 and 2.1.

I managed to find seven suitable photos of myself from identification cards and passports. One was 30 years old the rest within the past 12 years. All but one gave the same width-to-height ratio to one decimal place. The one exception, not the earliest photo, was not quite fully face on.



3 comments:

Barbara Tose said...

I recently used Photoshop to confirm that an "unknown" photograph was in fact my great-great-grandfather, John Crawford. Fortunately, I had a "known" photo of John facing the camera directly, as was the unknown photo. I re-sized them to match then used the opacity function to make one translucent and overlaid it on the other photo. The eyes,nose and mouth matched perfectly. As far as I'm concerned, it can't get more sure than that! A neat trick but you do need those full-face photos.

Cannuk said...

I am skeptical too. This sounds frighteningly like the eugenics of Nazi thought. I had hoped to move past that. For me, I am much happier doing my research and learning about ancestors through their deeds and time, rather than make such judgements.

WJM said...

Will phrenology and its bastard children never, ever, EVER die?