Saturday, January 26, 2008

Dominant and Recessive

My family by blood consists of 4 people, my mother, father, and older sister. All of them have black or dark brown hair and brown eyes, but me. I am the lone redhead with blue eyes in the family. That means there were plenty of jokes about my real father being the milkman from people who either didn't study or remember junior high-level human biology, or who simply thought that the joke was just too funny to let knowledge interfere with the potential guffaws as they displayed their sparkling wit via cliché humor.

For those who have blocked out the knowledge of rudimentary genetics which explains my family's physical disposition (or who just slept through it all to begin with), I'll mention that there are dominant and recessive genes. How these things work is rather complicated, but the way in which the concept is introduced to us in school is by talking about things like hair and eye color and explaining why there are more brown-haired and brown-eyed people in the world and fewer blonds, redheads, and green and blue-eyed people. Light hair and eyes are recessive traits (or so I was told) and if the genes for both light and dark hair and/or eyes genes are present, the dark characteristics will manifest.

In order to have a progeny with blue eyes or red hair, each parent must have a recessive trait's gene (such as red hair) and only pass on the recessive ones. So, my parents had the genes for both types of characteristics and passed the dominant ones on to my sister, but the recessive ones on to me. If the child has brown hair and blond hair genes, the child will have brown hair. So, the formula works out such that there's a greater probability of any person having dark hair and dark eyes, though the entire situation is probably about a thousand times more complex in the real world, but, trust me that the milkman did not have to be my father in order for me to be the lone person with light hair and eyes.

Lest you think this post has to do with educating you with my crude understanding of genotypes and phenotypes (and yes, I remembered those words from decades ago when I originally learned them and didn't pick them up from current research - hooray for the American education system), let me reassure you that my intention is to raise what I felt was an interesting cross-cultural difference.

This morning I was discussing blood type and personality with a student and asking her if she felt things like hair and eye color influence personality. For those who don't know, the Japanese believe blood type has a role in shaping character. It's always been my opinion that Japanese people hang personality traits on blood type because they are physically so much more similar than western folks. We can say a blond is dumb or a redhead temperamental, but they've all got dark hair. They have to go deeper than the surface to form their theories.

During the course of our discussion, my student asked me if there were more blond-haired, blue-eyed people than dark-haired people back home. I told her there were not and explained to her the whole dominant-recessive lesson we were taught in biology as the reason for this. At first, she was a little puzzled but then she had a moment of total understanding. She told me that Japanese kids learn the exact same lesson about dominant and recessive characteristics, but that they are taught that information using a different example as the basis for that information...can you guess what that might be?

To me, this is a fascinating reflection of each culture's residents' physical composition and the effect it has on their personality theories and educational methods. To you, well, perhaps it's just an interesting bit of trivia.


If you couldn't guess, the answer was: Blood type.


Lulu said...

ehhh....I just asked my boyfriend about this because it sounds weird that they would teach it this way but he said exactly the same thing!

I never knew my bloodtype until six months ago when I was having problems with my chest...they did blood tests etc and ECG`s to check my heart and I asked them to find out my blood type at the same time.

The doctor responded `What? You do not know your blood type? What happens if you were in an accident"

and I responded

"Are you trying to tell me that doctors beleive those bleeding to death when they say they have AB blood type...when they could be delarious from shock?"

and the doctor just looked at me. God, I hope they check!

I am A-.....until I found out many people had told me I was definitely A...including my bf and his family!

What are you?

lina said...

something wrong with my own education then. I didn't remember studying this in school. :P

Shari said...

Lulu: I think that doctors probably don't take a patients word for it, but they are still surprised at the depth of ignorance (in their opinion) which is displayed by not knowing one's blood type.

Being a deeply ignorant type myself, I don't know mine. I did have surgery at a Japanese hospital about 14 years ago so it was almost certainly typed (and I had my tonsils out around the age of 13 back home), but no one ever said, "your blood type is..." and how else was I going to find out?

Lina: Perhaps you were one of the nappers? ;-) I'm pretty sure it wasn't riveting stuff for most kids. They squeeze it in between dissecting worms and frogs and learning about how red and white blood cells work. It's also possible it wasn't included in all teacher's syllabi.

Thanks to both of you for commenting!

mike said...

Very intriguing! It seems that many cultures will tie personality traits to something relatively meaningless and least in our Western viewpoint. The traits for "A" pretty much spell out my personality! It is more accurate than the Chinese zodiac on all the Chinese restaurant placemats, or the mystical zodiac we know in the West. I never believed in all that stuff anyhow, but it is interesting to gives good insight into how a culture works.

I wonder if there is any mystical meaning to the Rh factor? I'm "-", and I am, unfortunately, negative most of the time...? I was always told I was A+, but my recent medical dramas lead me to learn that I am indeed A-.

...and thanks for bringing back memories of high-school Biology I & II! :P

(Two of my good friends are redheads, BTW! LOL!)

lina said...

I only know about my blood type when I was 26! That's only because I had so many blood taken for tests that year and I peeked at the chart. Nobody was like saying - OK, so you are XX blood type.

wintersweet said...

That *is* an interesting, subtle difference. :)

I think it's fairly normal for adult Americans to not know their blood types unless they've donated blood or had some kind of emergency. I only learned when I donated blood for the first time after Hurricane Katrina. This always shocks my Taiwanese and Japanese friends...I think a lot of them don't really believe in it, though, just like a lot of Americans don't believe in astrology.

The Nazi connection with the blood-type-personality thing is disturbing, and makes me wish that it weren't so popular.

Shari said...

Mike: I have only fond memories of biology classes. I loved all science except physics (which was more of a math class, and though I liked math, I never "got" physics). I think that the attributes for blood type and personality are the same as astrological ones. Everyone can see something of themselves in the characteristics. For instance, who doesn't see themselves as "creative" in some fashion?

The thing that I find interesting is this need everyone has to look to arbitrary external factors to "read" character. It points to a deep-seated need for an external locus of control, which is probably also related to the need to believe a higher power is in control of our destiny.

Wintersweet: I've never met a Japanese woman who didn't believe there was a blood type/personality connection, and I've never asked any men. That doesn't mean everyone believes it, but I think it's a little stronger a belief than the Western take on horoscopes. I don't think is because the Japanese are more "gullible" or whatever, but because the commercial aspects and ongoing prognostication associated with horoscopes have trivialized it such that it's impossible to take seriously. I don't think blood type determination is written about in terms of predicting one's future, so it's just a theory which they encounter now and then.

In a way, I think things get sillier the more they are expanded beyond being trivialities.

Thanks for the comments and for reading!