It's actually written: "For roughly 35% of people who discover aphantasia, it's a significant psychological stressor." It doesn't mean that 35% of the population has aphantasia. It means that among the 1-3% of the population who have aphantasia, 35% feel stressed when they discover it. I can see that the sentence could be easily misread. I have ADHD and dyslexia, so things like that happen to me all the time.
Hey Martha, you're right that many aphantasia studies involve small sample sizes, especially those conducted in lab environments. However, several larger studies are now converging around a 1-5% population estimate, with sample sizes ranging from 500 to over 5,000 participants.
The variation in findings primarily depends on whether researchers use a strict definition of aphantasia (total absence of imagery) or a broader definition (including dim or vague imagery). The Vividness of Visual Imagery Questionnaire (VVIQ) is the most widely accepted tool for measuring these rates.
Here are a few key population studies, including one with a multicultural sample:
https://aphantasia.com/research/10.1016/j.concog.2021.103243
https://aphantasia.com/research/10.21203/rs.3.rs-1703706/v1
https://aphantasia.com/research/10.3389/fpsyg.2024.1454107
You can always explore more in our research library at aphantasia.com/research.