1st, 2nd, and 3rd Cousins Explained

Genealogy research, the pursuit of tracing your ancestry, often involves a dive into complex family relationships. Cousins, those relatives who share a common ancestor but are not direct descendants of each other, can provide valuable clues in piecing together our family histories.

Below, we’ll explore the different types of cousins — 1st, 2nd, and 3rd — and how understanding these relationships can aid in your genealogical research.

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Who are 1st cousins?

Children of your mother’s or father’s brother or sister are your 1st cousins. They are genetically second only to your siblings, sharing only half of their DNA with you as one of their parents comes from the same genetic line.

You might’ve also heard about double first cousins, whose mother and father are each a sibling of your parents. They share the same DNA from both sides of the family so that they would be genetically identical to your siblings. This relationship is the closest possible, but it’s fairly uncommon.

Let’s take a look at an example from my family. My father was one of only two children, and my aunt had three. So, on my paternal side, I have three first cousins. On the other hand, my mother is one of three kids. Her brother had three children and her sister one, so I have four cousins on my maternal side. Combined, I am a first cousin to seven people.

» Learn more about 1st cousins once removed

Who are 2nd cousins?

If your parents have a cousin, their children are your second cousins. Like first cousins, they are in the same generation as each other, but they are one step further removed in the family tree than first cousins.

Using my cousin count again, my children have seven paternal second cousins and eight maternal, for a total of 15. The number between has now roughly doubled. Families with 20 or 30 cousins could have 60 or more second cousin relationships. While tracing your lineage, the number of surnames that appear can become impossible to keep straight.

My children have only 15 second cousins, but we have already added two additional surnames through marriage. Their second cousins are the two original surnames and five additional surnames. Documenting all the family names at every change is crucial as more appear.

» Discover all about 2nd cousins

Who are 3rd cousins?

3rd cousins share the same great-great-grandparents, meaning they are the children of two separate 2nd cousins. Now, this kind of relationship takes time to develop, so I have no example from my family.

But, 3rd cousins are the most common DNA relationship hints on genealogy websites like MyHeritage. It makes sense if you think about the fact that you likely know who your 1st and 2nd cousins are, but you may end up with dozens of additional surnames added to your family tree.

» Dive into the ins and outs of family relationships

A family tree illustrating family relationships.

Cousin relationships worldwide

Middle east

Some cultures — like the ones in the Middle East — divide cousin relationships differently. They use the term cross cousins for those related through the mother’s brother or the father’s sister, which they consider a distant familial tie.

On the other hand, parallel cousins are related through the same sex on both sides of the family tree. For example, a son’s relationship with the daughter of his mother’s sister, i.e., his maternal aunt. People of Central Arabia prefer a marriage between parallel cousins.

In fact, they have a custom called “the right of first refusal,” which says that a male parallel cousin has the priority when marrying his female counterpart. In this scenario, the family name remains unaltered, and the family wealth stays in the paternal line.

» Explore details about maternal and paternal lines

China

In Chinese culture cousins have specific titles that indicate their relation to one’s parents and their gender. For instance:

• 堂兄 (tángxiōng): Older male cousin on the father’s side
• 堂姐 (tángjiě): Older female cousin on the father’s side
• 表弟 (biǎodì): Younger male cousin on the mother’s side
• 表妹 (biǎomèi): Younger female cousin on the mother’s side

This system reflects a deep-rooted respect for hierarchy and generational differences, emphasizing that each family member has a defined role within the family structure.

» Learn more about Chinese surnames

Africa

In many African cultures, family extends beyond immediate relatives to encompass a broad network of extended family members, including cousins. This is especially pronounced in West Africa, where kinship is viewed as a communal endeavor rather than an individualistic one.

People look at cousins as siblings, playing pivotal roles in maintaining social cohesion and support. The extended family system is foundational, providing a sense of identity and belonging as individuals are often defined by their relationships within this network.

The African philosophy of Ubuntu, emphasizing interconnectedness and community, significantly shapes cousin relationships. The principle of ‘I am because we are’ underscores the importance of familial bonds, with cousins supporting each other emotionally and materially.

This interconnectedness fosters a sense of collective responsibility among relatives to care for one another, reinforcing the idea that raising children is a communal effort.

» Learn how to use African surnames in your research

How to place distant cousins in your family tree

Placing distant cousins in your family tree can be one of the most challenging genealogy exercises. Part of the frustration can come from feeling like you should know them and where they belong, but you have no idea. I’ve looked at DNA matches for distant cousins and wondered how I could not know who they were. But it’s important to figure it out.

The first goal is to identify a surname common to your tree. I first check if the cousin I’m trying to connect with is listed by their given name or married name. If I don’t know, I look at the parent’s names and check if I recognize their surname.

Next, I figure out at what point in my tree we share an ancestor. If they are showing as a third cousin, then I know we share a great-great grandparent. Can I look at the children of my great-great grandparents and find who they descend from? If not, I check each child at this level to see if I have missed placing any of their kids in the tree.

It can be easy to miss entering a child due to the time between census records as you get back into the 1800s. After I double-check this generation, I go to the next and then the last. Finally, I asked myself if I accounted for the divorces and remarriages. If not, I make sure I note them down, too.

» Find out how to contact your DNA matches

My experience with researching cousins

One line of research on a first cousin twice removed led me to find out about a first cousin three times removed named Aletha. I knew she had never married, but as I connected with her sister, also my cousin, I realized she had what we would call today special needs.

Rereading her father’s will suddenly made much more sense because he was leaving her sister an amount of money to take care of her and had also made provision as to how she should be taken care of should her sister fail. It was one of the most touching things I had ever read.

I have visited these cousins’ graves several times now, making sure their stones are cared for, and I always pause a moment and think about the father who cared and the sister who did the caring.

Using DNA tests to find your cousins

Through DNA testing, I have found multiple cousins. By the turn of the 20th century, my family came from four countries and moved between eleven states. No one had attempted to do the paternal side of the family tree before I started it, so my family tree had many holes, and finding cousins helped to fill them in.

One of the tools MyHeritage DNA offers is Genetic Triangulation, which helps you figure out how you’re related to another person. Through a DNA connection, I came into contact with a relative in a different county who subsequently shared a family birth record and a photograph I would never have had access to otherwise.

The cousin connection

As we’ve seen, cousins, while often overlooked in everyday life, play a vital role in our genealogical journeys. By understanding the distinctions between first, second, and third cousins, we can more effectively trace our family histories and uncover hidden connections.

By exploring these relationships, we not only deepen our understanding of our ancestry but also strengthen the bonds with our extended family.

» Start connecting with your cousins. Get a DNA kit today