17.0% identify as Protestant
17.1% identify as Catholic
0.4% identify as Mormon
10.1% identify as Jewish
2.5% identify as Muslim
3.0% identify as Hindu
16.6% identify as atheist
21.3% identify as agnostic
12.1% identify as "other"
* Some of the 12.1% who identify as "other" could be Christians who do not identify as Protestant, Catholic or Mormon, such as Orthodox Christians or Evangelicals who identify as "Christian" but not as Protestant. Other also includes, for example, self-identified pagans, Buddhists, Shinto, Chinese folk religion, and people who are spiritual but not religious or deist. Even if all of the 12.1% other identified as Christian (which is almost certainly not true), the percentage of self-identified Christians would be under 50%.
For the most part the politics of people with various religious affiliations are about what you would expect, but Harvard Muslims are among the most liberal religious affiliations on campus.
(These results are based upon a survey of "[c]onducted by The Crimson, the survey was emailed to all incoming freshmen on Aug. 6 and closed on Aug. 27, garnering responses from 1,184 students, roughly 71 percent of the 1,665-person class.").
Needless to say, Harvard's freshman class is not typical of the world at large, mostly because of very disproportionate numbers of non-Christians of all types.
By way of comparison, in 2008, according to the American religious identification survey:
Only 1.6 percent of Americans call themselves atheist or agnostic. But based on stated beliefs, 12 percent are atheist (no God) or agnostic (unsure), while 12 percent more are deistic (believe in a higher power but not a personal God).About 1.2% of Americans identify religiously as Jews, but more identify ethnically as Jews, 0.6% of Americans identify as Muslims, 1.4% self-identify as Mormon and about 1% identify as belonging to an Eastern Religion, which would include not only Hindu, but Buddhism and Shinto, for example.
Protestants, Catholics, and Mormons are all underrepresented at Harvard relative to the overall U.S. population (which isn't entirely a fair comparison as a significant number of Harvard undergraduates are drawn from abroad).
College aged adults are more secular than older adults, and only about 32% of "Nones" (which includes both atheists and agnostics as well as many unaffiliated people who believe in some higher power or are otherwise spiritual) in 2008 had that religious identification at age 12. Most "nones" in the United States are first generation "nones."
If the religious revival in the early 19th century that produced modern Evangelical Christianity and flipped the South from being the most secular part of the United States to the most religious was called the "Second Great Awakening" should the 1990s and 2000s which produced the strongest secular trend in history be called the "Great Nap"?