What's the human behaviour called that often makes us warp realities to appease another?

Question

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.

Answer 1

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.