Weathering Heights 
People who live high in the Andes and Himalayas have adapted 
both culturally and biologically to their environment 
by Charles A. Weitz 
The special problems of life at high 
altitude have intrigued Westerners since 
at least the time of the Spanish conquest 
of the Incas. Throughout Francisco Pi- 
zarro’s campaigns in the highlands, 
horses collapsed from exertion and sol- 
diers suffered from mountain sickness. 
Later, Spanish colonists experienced al- 
titude-induced infertility, and eventu- 
ally, most Europeans settled in lowland 
areas near the coast. In recent years, 
biological anthropologists and environ- 
mental physiologists have studied the 
relatively large native populations that 
live above 10,000 feet in South America 
and Central Asia in order to learn how 
these people cope, culturally and bio- 
logically, with the stresses imposed by 
their environment. 
There are three main forms of stress 
at high altitude: restricted food re- 
sources, cold, and — most severe of all — 
a reduction in the amount of oxygen 
reaching body tissues. This last phenom- 
enon, called hypoxia, is caused by low 
atmospheric pressure, which unless 
compensated for, reduces the amount of 
oxygen that diffuses through the lungs 
and into the blood. When lowlanders 
journey to high-altitude areas, they fre- 
quently suffer from a variety of hypoxia 
symptoms, including headaches, nau- 
sea, fluid in the lungs, loss of appetite, 
fatigue, insomnia, and labored breath- 
ing. For most people, these problems are 
alleviated as their heart, lungs, and cir- 
culatory system adjust. But even the 
best-adjusted lowlanders rarely are able 
to duplicate the activity patterns of na- 
tive highlanders. Since the basic cause 
of hypoxia cannot be attacked without 
sophisticated equipment, we may con- 
clude that the nature of highlanders’ 
superior adjustment to low atmospheric 
pressure is basically biological. Their 
adjustment to cold and nutritional 
stress, on the other hand, includes reli- 
ance on cultural means — learned behav- 
ior and technology. 
All humans show some rapid biologi- 
cal responses to stressful conditions. In 
the cold, almost everyone will produce 
more body heat through shivering or an 
elevation in the basal metabolic rate. 
72 Victor Englebert 
