A new study has put astrologers to the test, ultimately determining that they are confident in what they are saying, but no better at it than random chance.
Astrology mentions the planets and stars a lot, so can sound sort of science-y to laypeople, until you start looking into it. In fact, Gallup and YouGov surveys found that about 25 percent of Americans believe that the movements of stars and planets can affect people’s lives through some unknown mechanism.
There have been many scientific tests of astrology, and yet zero evidence has been produced in its favor.
One team, earlier this year, attempted yet another study to see if there was any validity to it, though of course not expecting to find any. They looked at a number of characteristics of 308 people (from religiosity to political persuasion) and various life outcomes (such as their mental wellbeing, achievements, and how busy their social lives were).
Using zodiac signs, they found no connection. However, they were criticized by astrologers for using Sun signs, whereas astrologers say they use “entire astrological charts”. The team decided to work with six astrologers to create a better test, to see whether astrologers could match people to their astrological charts.
The test, which is still available to take if you think you have astrological skills, was then put to 152 astrologers to see if they could perform better than random. The team found that more experienced astrologers were more confident about how many of the 12 people they had correctly assigned to their star sign. However, this added confidence did not translate to better performance, and they all performed in line with what you would expect from picking an astrological chart out of a hat. Those who considered themselves a “world-class expert” guessed 2.2 out of 12 correctly on average.
“If astrologers as a group had been able to do meaningfully better than chance, this study design would have supported the conclusion that astrology works,” the authors explained in a blog post. “But, as it turned out, astrologers in the study performed in a manner statistically indistinguishable from random guessing.”
The team was able to look at how astrologers from different schools of astrology (e.g. Chinese, Western, Mayan, and Renaissance) performed. They found that Hellenistic astrologers got the most right, 2.9 out of a possible 12, but this was still statistically in line with guessing.
The team attempted to find out whether, though they were wrong in their assessments, astrologers at least agreed with each other. For instance, did they all pick the same incorrect answer.
“The agreement rates among astrologers are very low, ranging from about 21 percent to 28 percent depending on experience level,” the team explained. “This suggests there is little consensus among astrologers when interpreting the same charts, even among those with high levels of experience.”
The team identified a number of limitations of the study, which has not been peer reviewed, including that the astrologers’ experience level was self-reported, and that no single study is definitive.
“An individual study can only provide strong evidence related to a claim, not definitive proof,” the team concluded. “Every study, including this one, should be interpreted in the context of other evidence.”
Unfortunately for astrologers, all the evidence (including far larger studies) so far points to no validity to their claims.
The study’s results are posted to Clearer Thinking.