Horoscope or other commonly used names for the horoscope in English include natal chart

Psychological criticism[edit]

Natal birth charts, or zodiac signs, are often used to predict a person's personality traits. However, the use of natal birth charts to predict personality is not valid or reliable. In a double-blind study that tested the zodiac's reliability to predict personality, an astrologer had to match a person's zodiac sign to their CPI (California Personality Inventory) result. The CPI is a reliable method to determine an individual's personality. It was found that the astrologers were not able to correctly match the zodiac sign to the CPI result beyond random assignment.^[12] This means that astrology is no more than a test of chance and it is not a reliable way to predict personality.

Similarly, the zodiac sign can be used to create horoscopes that predict the events that will happen in an individual's life. However, like using the zodiac sign for personality traits, using it for horoscopes is also unreliable. One astrologer's prediction for a horoscope is typically completely unrelated to the prediction of another astrologer.^[13] However, many people still believe their horoscope perfectly aligns with the events in their lives. There are some possible explanations for this. Horoscopes have vague wording and are based on typical everyday activities.^[13] Due to this, it is easier for people to relate to these claims and increase their belief that it is a real science. Also, a person's expectations typically lead them to bias the way they perceive information, so their expectations are confirmed. In a study, participant's horoscopes were paired with the events of their previous day. When the horoscopes were presented with the participant's zodiac sign, other participants were more likely to report that the horoscope matched the previous day's events compared to when their zodiac sign was not present.^[14] This shows how individuals will bias their perceptions based on the expectations. This makes horoscopes seem reliable, when they are not valid.