Global Health and Epidemics

Group Behavior

Behavioral ecology is the study of how evolution, more specifically natural selection, shapes

an organism’s behavior. The focus of this area of science is on how the behavior increases

survival and reproduction, also known as the adaptive significance of the behavior. One of

the branches of behavioral ecology focuses on group behavior. Individuals are constantly

competing with others for territory, food, mates, and other limited resources. By forming

social groups, species gain an advantage. Organisms as simple as bacteria to complex

organisms like humans display group behavior.

Examples of Group Behavior:

Defending Territory

Wolf packs maintain and defend the territories where they live, hunt, and raise their young. Non-pack members are run off or killed when they enter the wolf pack territory.

Protection

Prairie dogs live in large “towns” that can be a single acre, or span hundreds of acres. Within these towns certain individuals are responsible for watching for predators, and produce a warning cry that sends all prairie dogs within earshot to their burrows.

Group Foraging

Lions live in a pride and work together to take down their prey. The female lions decide when to hunt, and are capable of taking down large prey, such as wildebeests, when they hunt as a group.

Mating

Bands of wild horses normally have one dominant stallion that breeds the mares, and protects the band from danger.

Parental Care

After breeding and laying an egg, the female Emperor penguin passes the egg to the male, who will protect the egg for 2-3 months until it hatches. Once hatched, male and female penguins care for the young together.

Group behavior can impact choices and actions in human society as well. Group behavior

has evolved because membership can increase the chances of survival for individuals and

their genetic relatives. Large groups of people acting simultaneously to achieve a goal is

called herd behavior. Consider a large number of people in a stadium that catches on fire. Small groups of individuals may find quick and safe exits from the stadium, while large groups of people attempting to escape in the same direction are often trampled, or even killed. Herd behavior is also known as neighbor copying. The dynamics of group behavior can also be seen when people join protests, especially when they turn into mobs.

Group behavior is very important to public health. Due to the spread of worldwide travel,

urbanization, and globalization, the spread of infectious disease is more of a risk than it has ever been in the past. An epidemic occurs when the number of individuals who have

contracted an infectious disease is higher than expected within an area. A pandemic

occurs when this happens on a global scale. The fear of epidemics and pandemics can

have an impact on the behavior toward them. Understanding how individuals change their

behavior in response to an epidemic threat is important when forming public health policies for infection control.

Group behavior in these situations can be highly effective in slowing or stopping the transmission of infectious diseases. For example, through education and behavioral shifts to safer sex practices in Africa, the prevalence of HIV/AIDS infections have been reduced in developing countries. A survey conducted by NIH in 2009 determined that individuals were more likely to change their behavior based on:

• Media-communicated risk of the infection

• Individuals’ anxiety levels regarding possible infection

• Effectiveness of protective measures against infection

• Size of the household (particularly those with small children)

The health of populations on a worldwide scale is called global health. The field of global health aims to protect against global health threats regardless of borders, worldwide health improvement, and decreasing disparities in health access. In general, developed countries tend to be healthier than developing countries. For example, diarrhea is the 2nd leading cause of child death worldwide, due to poor sanitation in developing countries. The World Health Organization (WHO) is the dominant authority on global health. The WHO focuses on improving:

• global access to medicines

• public health in specific populations

• identifying causes and risk factors (epidemiology)

• research and data for policy decisions

• cost-effectiveness for allocating health resources