What's the human behaviour called that often makes us warp realities to appease another? Whenever people experience specific medical symptoms, they might research it online and find out that there is a possibility of a certain cancer being the culprit, they then might see that the chances of getting that cancer is 1 in a million. So they would often shrug it off as "Well that will never happen to me!", whereas that same person might go to the local store to purchase a lottery ticket that has a chance of winning set at 1 in 30 million and they then feel like the chance is high enough to win.

I am looking to find out if there is a particular name for this type of behaviour / thought process. I'm interested in research papers regarding these behaviours.
This is called optimism bias:


  ... a tendency for people to overestimate their likelihood of
  experiencing a wide variety of pleasant events, such as enjoying their
  first job or having a gifted child, and somewhat underestimate their
  risk of succumbing to negative events, such as getting divorced or
  falling victim to a chronic disease.


Optimism bias is a type of self-enhancement:


  ... a preference for positive over negative self-views.


and positive illusions:


  ... unrealistically favorable attitudes that people have towards
  themselves or to people that are close to them.