A taster's judgment can be prejudiced by knowing details of a wine, such as geographic origin, price, reputation, color, or other considerations.
Scientific research has long demonstrated the power of suggestion in perception as well as the strong effects of expectancies. For example, people expect more expensive wine to have more desirable characteristics than less expensive wine. When given wine that they are falsely told is expensive they virtually always report it as tasting better than the very same wine when they are told that it is inexpensive
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