Counting Generations for Genealogists: Understanding Family Lineages

Do you ever feel a little lost staring at your sprawling family tree? Names and dates are there, but understanding the real shape of your family lineage and how generations truly connect can be surprisingly confusing.

Misunderstanding generational links can lead to inaccurate timelines, muddied cousin connections, and even send your research down the wrong path. Imagine accidentally skipping a generation, misidentifying a relative, or missing crucial clues buried within your tree’s generational gaps!

By learning to count generations accurately, you’ll bring order to your family tree, understand complex relationships with ease, and gain a rock-solid foundation for deeper, more rewarding genealogical discoveries.

» Visualize your lineage and count generations by creating a family tree

What is a generation?

Social scientists often use “generation” to talk about groups of people born around the same time who’ve lived through similar big events, like wars or economic hard times. These events shape how they see the world and make them feel more connected to each other.

In legal terms, the idea of “generation” can also be part of what’s called “issue,” which means the direct line of your family: your kids (if they’re alive) and then their kids after them.

While genealogy is related to social science, when we talk about “generation” in family history, it becomes more about family lines and the simple passage of time through your ancestors.

» Learn genealogical numbering and track your ancestors across generations

How long is a generation?

In genealogy, “generation” really means the time it takes for someone to be born, grow up, and have kids. We call this time “generation length.” It used to be thought of as about 20-25 years. But, more recent research shows it’s actually closer to 29-33 years on average, even way back in history.

Keep in mind that generation length isn’t set in stone. It can change over different periods and from family to family, depending on health, culture, and where people live.

For example, the International Society of Genetic Genealogy points out that things like diseases, puberty and menopause, how long people live, and problems with having kids can all affect when people have children, which changes generation length. Also, what’s seen as the “right” age to get married in a society focused on work can make generation lengths longer.

On the other hand, religious beliefs about family planning that encourage getting married young and not using birth control can shorten generation lengths. If people move away from an area a lot, leaving fewer choices for partners, generation length can also become longer.

» Use genetic triangulation to validate your ancestral connections

How genealogists apply generational counting

Knowing about generations and generation length can really help with your family history research.

First off, understanding generations can help you guess birthdates when you can’t find records. Say you know someone named Malik was born in Dallas, Texas, in 1970, but you don’t know much about his dad. You can use generation length to guess his dad was born around 1940, which helps you know where to start looking for records.

Second, it helps you spot gaps in your family tree that need more digging. Think about Mary, born in 1844, who had her first baby in 1890 and saw her first grandchild born in 1910. Someone looking at this would see three generations right there.

But, if you look at the time between them, there’s a big 46-year gap between Mary and her child and only 20 years to the next generation. If you figure an average generation length is about 30 years, that 46-year gap is worth looking into.

It makes you wonder:

• Could the dates be wrong?
• Was there a change in her life situation between her birth and when she had her child?
• Did Mary have other pregnancies before her first child that we know about?
• Were there health problems that might explain the long gap?

Asking these kinds of questions can help you find out about inheritances or discover interesting family stories that can really mean something to your family.

» Create clear and concise family history records with genealogical tables

How to count generations in your family tree

To count generations right in your family tree, do the following:

1. Decide if you want to start counting from the youngest person (at the bottom of your tree if you picture it) or the oldest person (at the top). Whoever you pick is generation number one.
2. If you start with the youngest, then their parents (and people on the same level, like aunts and uncles) are the second generation.
3. Then, the next level up, their grandparents, are generation three.
4. If you start with the oldest person instead, then their kids (and others at the same level, like nieces and nephews) become the second generation. Going down from there, their grandkids are the third generation.

Here’s an example starting with the youngest person:

A family tree with the names of the generations.

Generations extend beyond family trees

The idea of generations isn’t just for family trees — it can also help us understand our place in culture and history. We can use “first,” “second,” and “third” generation labels to describe how far removed someone is from a major social, political, or cultural event in their family’s past.

For example, when someone says Jack is a third-generation college student, they mean he’s three generations away from an ancestor who never went to college.

Here’s another example: Blessing was born in Texas, but her parents were born in Nigeria. That makes her a first-generation Texan, and her kids will be second-generation Texans.

» Build a family legacy! Learn the key elements of a successful family tree

Culture and different ways of seeing generations

It’s important to remember that counting generations like this might not fit everywhere in the world or all legal systems, especially outside of Western countries. How people think about generations and family connections can be very different in communities that don’t focus on tracing just the father’s side of the family or straight family lines.

So, when you’re doing family history, it’s always best to learn about the specific values and traditions of the family, community, or period you’re looking into, especially when you’re thinking about generations.

» Find out how Theory of Family can help you connect with living relatives

Revealing the depth of your lineage

Your family history is a story told across generations, and learning to count them accurately is like learning to read its chapters. While the techniques are straightforward, the insights gained are profound.

As you continue your genealogical journey, let the concept of generations be your constant companion, illuminating the paths of your ancestors and enriching your connection to the past that shaped who you are today.