The age-group they're referencing as "Millennials" is arguably more constituted of iGen or Post-Millennials. The reliability of surveys and other information collections is undercut by sample validity, non-response bias, stakeholder bias, unverified respondents, participants who simply don't take the questions seriously, etc. Data offerings rarely provide associated error margins.
https://www.forbes.com/sites/trevornace/...-is-round/
EXCERPT: Millennials are most likely to believe the Earth is flat. Millennials in America sometimes get a bad reputation, this time for good reason. A recent survey found that just 66 percent of young adults aged 18 to 24 years old have "always believed the world is round." [...] Comparing religious beliefs, YouGov found that Democrats are slightly less likely to believe the Earth is round than Republicans (83 versus 89 percent, respectively). This, perhaps, could be an overprint of younger generations more likely to lean Democratic and older generations more likely to lean Republican. While YouGov didn't find a significant variation in flat Earth beliefs geographically, they did find a significant variation based on income level. The survey found that those with an income less than $40,000 (79%) are much less likely to believe the world is round compared to those with an income over $80,000 (92%).
MORE: https://www.forbes.com/sites/trevornace/...-is-round/
https://www.forbes.com/sites/trevornace/...-is-round/
EXCERPT: Millennials are most likely to believe the Earth is flat. Millennials in America sometimes get a bad reputation, this time for good reason. A recent survey found that just 66 percent of young adults aged 18 to 24 years old have "always believed the world is round." [...] Comparing religious beliefs, YouGov found that Democrats are slightly less likely to believe the Earth is round than Republicans (83 versus 89 percent, respectively). This, perhaps, could be an overprint of younger generations more likely to lean Democratic and older generations more likely to lean Republican. While YouGov didn't find a significant variation in flat Earth beliefs geographically, they did find a significant variation based on income level. The survey found that those with an income less than $40,000 (79%) are much less likely to believe the world is round compared to those with an income over $80,000 (92%).
MORE: https://www.forbes.com/sites/trevornace/...-is-round/