Luck of the Irish Ancestry

March is Irish-American Heritage Month, and we here at 23andMe wanted to take a quick look at our customers’ connections to the Emerald Isle.

Although Irish immigration peaked in the United States in the mid-19th century, a significant number of 23andMe customers have much more recent ties to Ireland. To more closely examine which of our customers have Irish ties, we looked at how many customers reported to having Irish grandparents across the United States.

We saw patterns in recent Irish ancestry that mimicked historical patterns of migration to the country. Looking at aggregated data from customers who consented to participate in research and reported that at least one of their grandparents was born in Ireland, we were able to see what states had higher concentrations of Irish ancestry than others.

 

23andMe’s data showed concentrations of people with recent Irish ancestry in the Northeast — Massachusetts, New York, New Jersey, Connecticut, New Hampshire, Maine, and Vermont. That data also showed fewer individuals with recent Irish ancestry in the Deep South, and the Southwest. It’s important to note that this is not mapping genetic ancestry, rather it is looking at concentrations of where people who reported to having grandparents that were born in Ireland currently live.

While this data was not the most surprising to our population geneticists, what’s interesting is  that the state-wide segmentation mirrors Census data on reported Irish ancestry and long-established patterns of where Irish immigrants have settled since first arriving in the country.


The United States has a long history of people from Ireland crossing the Atlantic to seek a new life here, but the biggest waves of migration ended almost a century ago. Now, a little over 10 percent of people in the United States say that they have Irish ancestry — that’s about 32 million people. History and migration patterns mean that individual states, such as Massachusetts in the Northeast, and certain communities, like Plymouth County south of Boston Massachusetts, have higher concentrations of people with Irish ancestry in the country, according to the U.S. Census Bureau.


Earlier this year, 23andMe announced new content-rich pages called Ancestry Detail Reports, which offer a more granular view of your ancestry with 1,000+ new regions, and snapshots of the places your DNA connects you to. With this new update, 23andMe can now map our customers’ ancestry to more than 26 sub-regions in Ireland. Check it out, and see if you have luck of the Irish…ancestry.