Heated rhetoric around the topic of immigration in America can lead to misleading facts and figures about who is entering the country, where they are coming from, and what brings them to the United States. For a clearer understanding of those facts and figures, we turned to the non-partisan Pew Research Center.

Mark Lopez (Courtesy of Mark Lopez)

Mark Hugo Lopez is the director of Hispanic research at Pew and works with the numbers on immigration across the board. The alto-sax playing former academic says he is committed to telling interesting stories using data to back them. Lopez says he was a geek in high school, keeping journals about topics that interested him — such as the gross national product.

Lopez was born and raised in the Los Angeles area; his grandparents came to the United States from Mexico. He says that had he not entered the realm of data, he might have pursued a career as a journalist because of his commitment to telling people's stories.

Smithsonian Second Opinion spoke to Lopez about trends in immigration to the United States, among other topics. This interview has been condensed and edited for clarity.

What is an immigrant?

The definition of an immigrant is somebody who was born in one country by moves to another. That's a pretty straight-forward definition, but of course, the question of how those people adjust in their new destination country is really where you have a lot of differences. For example, somebody who might move from Canada to the United States and they speak English. They've probably gone to school in a school system that's very similar to what you would see in the destination that they've settled in in the United States.

One can be an immigrant in a number of different ways. Somebody who's new to a place. We might be talking not just about people who are international migrants, but perhaps also somebody who's moved from California to the East Coast.

That too has some elements of a migrant experience that could be both quite interesting to hear the person's story or could have some elements that are shared and in common with somebody who may have moved from Canada to the East Coast.

However, somebody who say moved from a place like Myanmar to the United States, that might be a much bigger transition because of language differences and also because of educational attainment differences, and perhaps even the status of the person. The person may even be a U.S. refugee, which is somebody who is technically an immigrant, but that's a different part of the immigrant's experience altogether.

What is an American? Can an immigrant ever be truly American? What about their children? Their grandchildren?

Our surveys [of Spanish-speaking immigrant populations in particular] have shown that there are a couple of patterns that are immediately obvious.

First, Spanish diminishes in use across generations. English becomes the dominant language by the third generation even though those third-generation folks say they would love to learn to speak Spanish and they think it's important that you speak it. Frankly, most of them are English speakers first.

Second thing that's interesting is that by the third generation, you do see patterns of educational attainment, labor market engagement, that look very much like the general U.S. public. By the second generation and by the time you see those U.S.-born children of immigrant parents, they oftentimes look like other young people in their attitudes, in their affiliations, in their aspirations. It's hard to actually distinguish them in some way.

In Europe, they've had a large wave of immigration over the last 50 years just like we have. They've put into place many programs to formally integrate people into French culture, into German culture. In many respects, it's the opposite way of doing things the way we do here in the States. Yes, there are policies at the state level and city level that are designed to help immigrants integrate in the United States. It's not universal, but say New York City, for example, has immigrant high schools.

That's an example of New York City providing assistance with immigrants to help them integrate and understand how the city works. The question is, where is integration perhaps happening best, and what does it really mean to integrate? Well, as the U.S. becomes more diverse, I think that question of what is integration does change over time, although we do see in Hispanics the growing use of English as one example of integration.

Do you currently see a demographic change in the types of people wanting to come to the United States?

The United States has about 45 million immigrants, and that's more than any other country in the world. In terms of immigration, the United States is the world's leading destination for today's immigrants. Worldwide, there's about 245 million immigrants, so the U.S. has maybe about one-fifth of the entire world's immigrant population. The U.S. also takes in more refugees than any other country that are identified by the United Nations, so not only is the U.S. a magnet for what we call voluntary migration, people choosing to come here, but it's also the biggest receiver of refugees.

Even though other countries like Canada and Australia have recently pointed to their increasing numbers of refugees that they're taking in, the U.S. still does take in more. When we talk about the story of immigrants in the United States and whether or not we're starting to see any changes in inflows and who's coming and what flow changes we've observed, it's actually hard to say between anything in the last year. If anything, it looks like we're still getting about a million immigrants coming to United States legally every year.

In fact, we've seen a rise in the number of immigrants from Africa coming to the U.S. in the last 10 to 15 years, many of them with college degrees, many of them with doctorates, for example. On the other side of this, we continue to see immigration from Central America of Salvadorans, Hondurans, and Guatemalans. Those numbers continue to rise even as Mexico has declined, and they tend to be less educated and oftentimes younger. When you look at these profiles, you can see it's quite a diverse population of people who are coming to the United States, perhaps even more diverse now that Mexico is not as big a part of the story as it was just about a decade ago.

We still have unauthorized immigrants, and all of the big flows from Latin America, particularly from Mexico that we had been observing in the early 2000s, those are already well underway. We're at a decline, and that decline was well underway even before the 2016 presidential election. Changes that we've seen in terms of migration, it does seem that we've seen very much.

What do numbers show about unauthorized or undocumented immigrants?

It's hard to get good statistical data out of the criminal activities of undocumented immigrants just because oftentimes, if somebody is undocumented and they do commit a crime, they're oftentimes immediately deported after they serve their term. They're no longer in the U.S., and it's hard to get that information on them, but all the evidence that researchers have found seems to suggest that crime does not necessarily rise with the rising undocumented population in the country.

In fact, the national level as we saw the undocumented immigrant population rise to 11 million, 12 million people, the crime rate in the United States fell, so that's one big giant sweep of data. It doesn't get it at local level, but it does give you the stats that here we have this surge in unauthorized immigration, but at the same time, a record low in the crime rate.