Family history research involves documenting relationships between people, but defining ‘family’ isn’t always straightforward. Modern genealogy research must account for diverse family structures beyond the traditional nuclear family.
Who do you research when you research your family history? Who is your family?
In family history research, genealogists examine and document relationships between people who are considered to be members of the same family. However, there is no single definition of family. The way that you think about family defines who you include in your family history research and how you document it.
This post was originally published in December 2022 and last updated on 28June 2025
Definitions of Family
An English dictionary definition of family says something like this:
‘a group of persons united by the ties of marriage, blood, or adoption….the essence of the family group is the parent-child relationship…At its most basic, then, a family consists of an adult and his or her offspring. Most commonly, it consists of two married adults, usually a man and a woman (almost always from different lineages and not related by blood) along with their offspring…known as a nuclear family, is believed to be the oldest of the various types of families in existence.’ (Britannica.com)
The concept of a household is usually intertwined with the concept of family. A family is often defined as living in the same household, and a household may contain more than one family. Non-related people in the household are usually not regarded as family. A household can also comprise a group of unrelated people.
The Australian Bureau of Statistics defines family as:
‘two or more people, one of whom is at least 15 years of age, who are related by blood, marriage (registered or de facto), adoption, step or fostering, and who are usually resident in the same household.’
Types of Family in Genealogy Research
Most families throughout history didn’t follow the nuclear family model. Understanding this helps you research and document the complex relationships you’ll actually find.
Nuclear Family
The ‘nuclear’ family of two parents of the opposite sex with their children may have been the most common form in many societies. However, it has never been the only form of a family.
In my own family history, I have discovered a family which included children living with their grandparents (early 1800s), two widowed parents with their own children who cohabited (late 1800s) and an unmarried man living with his married sister and her husband (mid 1900s). I am sure that each of these considered themselves to be a family.
Households
Tying the concept of family to a household is also problematic.
Related persons who live in separate households may still participate in family activities together, such as sharing their meals together and child minding. I recall a number of relatives who lived either next door to each other or on the same street and acted like one big family despite living in different houses.
Other Family Types
It is tempting to adhere to societal definitions of the so-called ‘traditional’ family unit. In reality, a family can be made up of anyone who that family considers to be a part of it.
It is not just that the concept of family has changed over time, it also differs between cultures, countries and communities, and even between families or individuals. And, a person may belong to different families at different times.
The concept of family is dynamic. Your family history research may change your own perceptions of family. As you research and grow to know more about your ancestors, you may expand your definition of family.
Biological and Non-Biological Families
If you incorporate DNA into your research, you may find that your concept of family expands even further.
In DNA research you have to research people who are related to you much more distantly than you would have done before. You aren’t just adding siblings, aunts and uncles to your family history, but people such as second cousins three times removed and men who fathered children but never even knew it.
And then there is that issue of whether family are only people you are related to biologically.
When I found out that my father was adopted, I was faced with this question. Were the grandparents and cousins that I grew up with still my family? Or was my ‘real’ family the people who I was related to biologically but never met?
After some soul-searching I decided that they were all my family. My father now has two sets of parents and ancestors, both as equally important as the other.
Family Research Methods for Complex Relationships
Identifying a person’s parents is at the core of genealogy research. This allows us to trace the line back in time.
You identify the parents by examining sources about the families that the parents and child belonged to at different periods of their lives. The sources may relate to an individual, a couple, a family or a household. They may also mention other members of the family or household. When analysing the sources, you try to establish the relationships between each person.
Understanding the varying nature of family structure helps you analyse sources and compile your family history. It can make you more conscious of the need to identify the nature of a relationship in an apparent family or household.
Documenting Your Family History
Many genealogists document their research using printed family group sheets. The standard format for these forms is based on what is often called the traditional family unit: husband, wife and children. However, as I have discussed, families can take different forms and it can be challenging to make them fit into printed family group sheets.
Family history software and online family tree platforms tend to be more flexible. For some time, they have allowed us to include multiple partners for a person, recognising that they may marry multiple times. They have also allowed us to include parents who did not marry, and distinguish between biological and step-parents.
More recently, they have changed to allow the documentation of a wider diversity of family and relationship types.
Ancestry, for example, allows you to add multiple sets of parents to a person in your family tree. You can also define the relationship of each as biological, adopted, step, foster, related, guardian, private or unknown.
Legacy Family Tree software has similar functions, but also allows you to add your own custom relationship description. The child can also be given a status, such as adopted, foster, illegitimate, stillborn or twin.
Family history software and online family tree platforms also have functions which help you identify the relationship between two people, even if that relationship is very distant. Legacy Family Tree software, for example, has a setting that adds a label to each person stating their relationship to the starting person (usually yourself). It also allows you to print out a chart showing the line of relationship between two people.
Documenting Households in Family History
Documenting households in family history is a little trickier.
You can add a ‘fact’ to each person with information about their residence at different points in time. However, there does not seem to be an easy way to gather a list of all the people in the same residence at the same time (a list of a household). If anyone has a good system for doing this, I would be happy to hear from you.
If there was a person in a household that was unrelated to the family, I believe it is still worth adding them to your family tree as they clearly had some type of relationship even if it was not biological. I add these people to my tree as unlinked individuals, then add ‘facts’ to them indicating that they were in the same residency as a particular family.
Next Steps
Take a look at your family history and the way that people are grouped together. Be mindful that they may not follow the model of a nuclear family.
Examine your online family tree or family history software and make adjustments to document the relationships more specifically, if you have evidence to do so. Start by adding the categories of step-parents and adopted parents, and move on from there.
For more of my articles about documenting family history and family history software, go to the Document page.
For more of my articles about research methods for family history, go to the Research Methods page.
Main image: Squair family wedding, from the archives of the Society of Australian Genealogists.
About the Author
Danielle Lautrec is a genealogy educator, researcher, and author of The Good Genealogist. With qualifications in history, family history, and historical archaeology, she teaches for the Society of Australian Genealogists.
