The placebo effect best illustrates the impact of positive expectations on feelings and behaviors. This type of medical treatment does not contain any active ingredients but often still produces a physical effect on the individual.Placebos can reduce the symptoms of numerous conditions, including Parkinson's disease, depression, anxiety, and fatigue.
Pretty sure it'd be Native American
The chance that a certain event will occur is known as a probability of this event.
Knowing the probability of an event helps predict whether it's likely that this event will happen: if the probability is high, it will likely happen. If it's low: it will likely not happen.
