Answer:
Re-emerging infectious diseases.
Explanation:
These types of diseases that were exterminated but now have came back are typed as 'Re-emerging diseases'. The diseases where once eradicated but now they have mutated and evolved to stronger strains. The diseases that were once controlled have now have had more reported cases and gaining popularity have 'emerged' once again into the world.
Due to parents not wanting to vaccinate their children from common diseases like polio and measles, this could become an epidemic.
One of the things that psychology focuses on is behaviour, in fact, some psychologists focused only on this. However, modern psychology focuses more on the cognitive processes, and it's also called "cognitive psychology"
so: Behaviour and cognitive processes
