How in touch with the world do you think you are? A new survey designed to measure people's misconceptions about common topics such as obesity, religion, and wealth shows we don't know nearly as much as we think we do.

The Perils of Perception 2015 survey from UK-based research group Ipsos MORI quizzed respondents from 33 countries around the world to see how on point (or off base) they were, ranking each country on an "Index of Ignorance" that names and shames the nations that know the least about the way things are.

Take wealth for example: how much wealth does the 1 percent really control? It turns out most developed countries greatly overestimate this. For example, Britain estimates the 1 percent owns 59 percent of its wealth, whereas the real figure is 23 percent.

Many other countries, however, including Peru, India, and Russia, underestimate how wealthy the 1 percent is. In Russia, the 1 percent holds 70 percent of the nation's wealth, whereas the average Russian assumes 23 percent is the reality.

Almost every country surveyed underestimated the extent to which their populations are overweight or obese. On average, among the countries surveyed, the actual figure is 54 percent, whereas people think it's 40 percent. India, Japan, China, and South Korea are the exception to this (although they're also the countries where the population is much less overweight).

Many nations overestimate the extent to which they are non-religious. Most remarkably, Indians believe a third of their country is non-religious, when in actuality, less than 1 percent say they don't take part in a faith.

"Across all 33 countries in the study, each population gets a lot wrong," said Bobby Duffy, who led the survey. "We are often most incorrect on factors that are widely discussed in the media or highlighted as challenges facing societies… We know from previous studies that this is partly because we over-estimate what we worry about – as well as worrying about the issues we think are widespread."

So which countries rank as the most out of touch with the population that surrounds them? Mexico unfortunately tops the Index of Ignorance, followed by India, Brazil, Peru, and New Zealand, with the latter being the least accurate of all the developed countries surveyed.

Among the countries that suffer the least misconceptions about their society, South Korea was the most self-knowing nation, and was trailed by Ireland, Poland, China, and the US.

"There are multiple reasons for these errors," said Duffy, "from our struggle with simple maths and proportions, to media coverage of issues, to social psychology explanations of our mental shortcuts or biases."

The researchers also note that the countries that tended to do the worst on the survey have relatively low Internet penetrations.

"[G]iven this is an online survey, this is therefore likely to reflect that this more middle-class and connected population generalise from their own experience rather than consider the much greater variety of circumstances in the full populations of their country," said Duffy.