Ask someone to close their eyes and picture a typical homegrown, American recruit for the Islamic State in Iraq and Syria. Chances are the image that springs to mind is of a brown-skinned person with an immigrant background, likely with ties to the Middle East, South Asia, or North Africa. That image of the average accused terrorist might be out of date, a new study published by the Rand Corporation suggests. In the study, “ Trends in the Draw of Americans to Foreign Terrorist Organizations from 9/11 to Today ,” which sought to explore why ISIS has relative successes recruiting in the U.S., researchers found that in recent years the most common demographic profile for an accused terrorist motivated by “radical Islam” has been a native-born American, either white or African-American.

As the nature of terrorism changes, the average “jihadi” in the United States is starting to look less like the type of person President Donald Trump wants to ban from the country.

As the nature of terrorism changes — both ideologically and under the influence of new technologies like social media — the average “jihadi” in the United States is starting to look less like the type of person President Donald Trump wants to ban from the country. The finding has serious implications for immigration policies like the so-called Muslim ban, which posit terrorism as something naturally emanating from immigrant communities, particularly of Middle Eastern extraction.

The Rand study identified 476 individuals implicated in cases of “jihadist terrorism” in the United States in the 16 years following the September 11 attacks. (The Intercept also maintains a running database of terrorism cases called “Trial and Terror,” which includes a broader scope of offenses.) Of the individuals in the Rand study, 206 were of Middle Eastern, North African, and/or South-Central Asian background, accounting for about 43 percent of the cases. The study, however, notes that this number is “somewhat surprisingly” trending downward over time, stating that “in percentage terms the number of individuals of Middle Eastern, North African, and/or South Central Asian descent has declined in recent years relative to other demographics.”

The main driver of this phenomenon appears to have been the rise of ISIS. In the years 2014 to 2016 — the peak years of ISIS recruitment in the U.S. — the study found that a majority of so-called jihadi terrorist recruits in the country were Caucasian or African-American, two demographics not generally associated with immigration. In those three years, 79 percent, 57 percent, and 62 percent of “jihadist terrorism” cases came from the combination of those two groups.

The findings show that the popular stereotype of who becomes a homegrown militant in the era of ISIS is at odds with the actual data.

“Perhaps most notably, individuals radicalized by ISIL’s influence have ethnically and racially not tended to be of Middle Eastern, North African, or South Central Asian descent; only 26 percent of persons fit this profile, compared to approximately 53 percent of al Qaeda recruits and supporters,” the authors, Heather Williams, Nathan Chandler, and Eric Robinson, wrote, using the alternative acronym ISIL instead of ISIS. “Conversely, about 65 percent of U.S. persons drawn to ISIL since 2013 have been either African American/black or Caucasian/white.”

This is obviously not to say that Caucasians or African-Americans are thus inherently more likely to support ISIS. The number of people from either demographic who have turned toward the militant group is minuscule, particularly among African-Americans who have large and long-established Muslim communities in the United States. What it does suggest, however, is that terrorism in the U.S. today is much more of an American problem than an immigrant one. People implicated in terrorism plots in the United States in recent years are more likely to have no pre-existing ties to Muslim-majority countries.

“The portrait that emerges from our analysis suggests that the historic stereotype of a Muslim, Arab, immigrant male as the most vulnerable to extremism is not representative of many terrorist recruits today,” the study notes. “Instead, recruits are more likely to be Caucasian/white or African American/black; they are more likely to be U.S. born; and they are more likely to have converted to Islam as part of their radicalization process.”

Experts say that these findings throw even more cold water on Trump’s argument that banning Muslim immigrants from the United States is helpful for national security.

“This study supports what most terrorism scholars have been saying for a long time. There is no single solution to the threat faced by groups like ISIS,” said Amarnath Amarasingam, a counterterrorism expert and senior research fellow at the Institute for Strategic Dialogue.

“Demonizing refugees and immigrants — whether with respect to the Muslim ban or even more recently the ‘unknown Middle Easterners’ coming from Latin America — only serves to dehumanize already marginalized communities. It has nothing to do with national security.”

The study also shows a generational shift in the nature of this kind of violent fundamentalism. The original Al Qaeda organization that went to war with the United States in the late 1990s was mainly comprised of people with roots in the Middle East and South Asia, as well as some from sub-Saharan Africa. These individuals tended to be relatively educated, with a particular overrepresentation of people trained in engineering-related fields.

In contrast, the individuals implicated in domestic “jihadist plots” in recent years — most of whom have gravitated toward ISIS — tended to be younger, less educated, and seemingly driven as much by personal pathology as much as geopolitics.