05/19/2015 10:13 am ET | Updated May 19, 2016

Are Hindus Being Undercounted in Religion Surveys?

Last week, the Pew Research Center released a report on how Americans identify in terms of their religious beliefs, noting the growth of non-Christian traditions within the country.

According to Pew, Hinduism is now tied with Buddhism as the country's fourth-largest religion, with approximately 2.23 million adherents. What's fascinating about this count is that, according to the survey, the population of Hindus in the United States jumped by over 1 million since the last time Pew collected the data, which led to the research center's acknowledging of a potential undercount last time.

Before we get to the prospect of undercounting, it's important to touch on the improbability (or impossibility) of any group jumping in population by 1 million in just six years. Even if, as Pew suggests, the growth of Hindus is fueled by immigration, the statistics of immigration from countries with high Hindu populations (India, Nepal, Guyana, Fiji, Bangladesh, Suriname, Trinidad, Sri Lanka, and Mauritius) would not be able to match the jump in numbers between surveys.

In 2008, Hinduism Today, relying on U.S. Census Data, found that the number of Hindus in the United States was roughly 2.3 million. Even if there was a reconciliation of numbers between the surveys, and the Hindu population has not grown as highly as Pew suggests, there's a distinct likelihood that the Hindu population in this country is upwards of 2.5 million.

Why is there such a disparity between the Hinduism Today and Pew findings? Part of it might just be the respondent and population size and composition, as well as statistical assumptions about just who Hindus are. Hinduism Today, published by the Kauai Hindu Monastery and read widely by the Hindu-American community, likely had a larger and more responsive sample size, while Pew might have relied more on "traditional" barometers of Hindu community growth, such as concentrations of Indian Americans. Even then, the likelihood of getting a reflective and responsive sample size might have proved to be challenging, given that minority religious groups, particularly those whose populations tend to significantly comprise immigrants, are often reluctant to participate in surveys, as Pew noted in a 2007 study of Muslim Americans.

In addition to the lack of participation, the potential undercounting of Hindu Americans in these religious surveys might be attributable to three factors: oversampling of Indian communities and undersampling of non-Indian Hindu communities; Hinduism's decentralization; and diverse interpretations of what it actually means to be Hindu.

While many Americans conflate Hindus with people directly from India (or the Indian subcontinent), a good part of the Hindu-American population is made up of Indo-Caribbean people, as well as those from countries such as Fiji, South Africa, Mauritius, Indonesia, and Malaysia. It's also likely that second- and third-generation Hindus aren't part of the samples because fewer of them are part of the temple-attending community. Moreover, because Hinduism is largely considered a non-proselytizing religion, there aren't any universally recognized conversion processes into the faith. While the Pew study estimated roughly 10 percent of Hindus are converts, Hinduism Today estimates that number to be much higher. Even from a distance, groups like ISKCON (Hare Krishnas), Art of Living, and the Sathya Sai Baba movement have a significant number of those who have adopted Hinduism, underscoring the universality of Hindu philosophy.

The other challenge of tracking the Hindu community is the religion's inherent decentralization. The majority of Hindus do not regularly attend temples or religious centers, and the very personalized nature of practice -- as well as the lack of signifying features among most practicing Hindus -- and the lack of doctrines make Hindu Americans fall outside the traditional American definition of organized religion.

Lastly, Hindus rarely chest thump their religious identities in the public sphere, and since there is no scale of religiosity, a Hindu can be an atheist (and there are more than a handful who identify as atheist Hindus) or a devout Bhakta -- and everything in between. Therefore, putting the Hindu population in the 2-million range still doesn't tell the whole story of who Hindu Americans are, how they identify, and how they practice. While the ambiguous diversity of just who a Hindu is may lead to more undersampling -- and undercounting -- in future religious landscape surveys, it still reveals a lot more about the organic and continued growth of a religion that, over thousands of years, has shown itself to be remarkably adaptable to any environment.

That qualifiable growth, more than the numerical one, is worth celebrating.