What has research on social support and rates of mortality shown?

People with less social support have higher rates of mortality.

Explanation:

Not all people will be able to thrive in the job market competition. Which mean large portion of the population might not be able to fulfill their basic needs. (health care, foods, etc)

Social support will provide some sort of safety net for the citizens to at least fulfill their basic necessities when they fail to do so from their day to day job. When basic necessities are met, mortality rate tend to be decreased.