Chapter 12: Physical Health:
1) Different selection pressure à divergent of innate physical propensities
2) Different cultural pressure within the lifetime of this induidualà divergent of acquired physical propensities.
Innate Physical Propensity
• Some biological variation is due to differences in inherited genes. The most salient example of biological
variation is skin color.
• Skin color is strongly correlated with the amount of ultraviolet radiation (UVR) that reaches the surface in
different parts of the globe. People need light enough skin to allow sufficient UVR be able to synthesize
Vitamin D but dark enough skin to prevent the breakdown of folic acid
Ecology, Economy,and Genes
• There are also some cases where cultural factors have influenced the genome.
• For example, people from cultures in which cows have been domesticated for a longer period of time are
more likely to have a mutation that allows them to digest lactose into adulthood.
• Few Asian and African can fully digest milk. Most of the European are categorized that are able to drink
milk without any problem. Thus culture shapes our genetics.
Acquired Physical Propensities
• Thus far, the majority of adaptive gene variations have been associated with thermal regulation, resistance
to pathogen, and enduring dietary practices. There is much variation associated with nonadaptive genetic
• In addition to genetic variation across populations, there is also some acquired physical variation. That is,
various aspects of people’s bodies may change because of cultural experiences within single generations.
• One example of acquired physical variation is that the Moken, sea gypsies from Southeast Asia, have twice
the underwater visual acuity as Europeans.
• From a young age Moken children swim underwater to retrieve seafood.
• Their enhanced underwater visual acuity appears to be the result of experience rather than a genetic
adaptation. Some research suggests that this ability can be trained into American.
Obesity and Diet
• One source of evidence for the role of culture is that obesity rates have been growing remarkably across
many countries. Japanese are very low as compare to the USA. But the pattern is that same in that they are
all going up for all.> change in people diet is the cause of this ( culture)
• Frech Paradox: Why are French thinner then American?
• Within the West itself, there is considerable variation in obesity rates.
• France, for example, has about one fifth the obesity rate of the US despite the more fat food.
• One account for this is that the French live in a culture where food comes in smaller portions than it does in
• Paul Rozin and colleagues set about measuring food serving sizes in the US and France. There were some
Large American Portion:
• Yogurt containers are about 80% bigger in the US than they are in France
• McDonald’s French fries are about 70% bigger in the US than in France.
• Meal at Chinese restaurant in France is less than 60% the size of a meal at a Chinese restaurant in the US.
• Recipes in the US call for larger portions of ingredients than they do in France.
• Even fruit is bigger in the US! About 28% larger for the same fruit.
• Curiously, cat food cans are slightly larger in France than in the US.
• Historical data: Large American portion sizes are the result of fairly recent cultural change. Here are some
examples of changes since the 1950s.
Attitude towards Foods
• French savor their food more, and take more time eating it (thus, healthy people) • Americans are more likely to associate food with fat.
• People were asked to choose which of the following options is the best metaphor for the human body in
relation to its diet: a tree, a car, or a temple.
• The most common answer, by far, for French was tree this was the least common for Americans, who
preferred a car metaphor ( attitudes towards food is different)
• People from France, belgium, japan and US and accessed their attitude. The size of the face linked to the
people’s response. + Attitudes =large and happy face
• Male in all culture have positive attitudes regarding food.
• French males look the most happy
• The least happy face was American female ( association with food products)
• Thus a substantial cultural difference towards food
Culture and Health
Socioeconomic Status (SES) and Health
• The higher one’s SES, the longer one lives, on average. Even relatively small increments are associated
with longer life outcomes
Burkina Faso Research
• In north east Burkina Faso there are three ethnic groups that coreside the Fulani, Mossi, and Rimaibe.
• The Mossi and Rimaibe have evolved much genetic resistance to malaria.
• The Fulani(recently moved into this region) lack most of the genetic resistance to malaria.
• BUT The Fulani have SES
• Conclusion: Despite that they have less genetic resistance to malaria; the Fulani contract malaria less often
than do either the Mossi or the Rimaibe. ( in nonindustrialized)
What Causes the Lower Health Risks for Higher SES People?
• Access to health care cannot explain all of this relation ( many societies all are able to get health care)
• Lower SES people are more likely to engage in unhealthy habits, such as smoking, eating fast food, and are
less likely to exercise. However, the SES differences still remain if you control for health habits.
• One mediating role between status and health outcomes is stress level
Stress and Health
• Stress affects health in at least two ways.
– First , when people are stressed they’re more likely to engage in healthcompromising behaviors l