Modern Software Experience


genealogy theory

Classical Genealogy

Classical Genealogy is genealogy without the complications introduced by modern medical techniques. Its counterpart is Modern Genealogy; genealogy complete with the complications introduced by modern medical techniques.

more than one

What is Genealogy called attention to the fact that most definitions of genealogy do not fit the reality of genealogical research. Two Genealogical Dogmas pointed out that two widely held genealogical dogmas conflict with each other, and introduced the heresy that you have more than one genealogy.


genealogyrecord types
marriage records, divorce records
adoption records
foster records
guardianship records
migration records
birth records (baptism records)
death records (burial records)

This framework for classical genealogy recognises three different genealogies; biological genealogy, official genealogy and legal genealogy.
The diagram shows how major record types fit into the framework, how the different genealogies relate to these record types and each other; legal genealogy is stacked on top of but different from official genealogy, which is stacked on top of but different from biological genealogy.

biological genealogy

At the basis of classical genealogy is the biological genealogy.
A biological genealogy is a genealogy made up of biological parent-child relationships.
A biological genealogy cannot be constructed from official records, because there are no records for biological relationships. There is only phenotype.

official genealogy

An official genealogy is a genealogy made up of just the truly vital records, including officially recorded parent-child relationships.
There is no guarantee that any official relationship matches the biological relationships. The official genealogy is merely the best approximation of the biological genealogy that official records can offer.

legal genealogical

A legal genealogy is a genealogy made of all legal family relationship. This includes many relationships, such as marriage, divorce and adoption, that have changed the legal and social relationship of those involved. Some of these legal changes, such as adoption and name changes, may obscure the official genealogy.


biological versus official

The official genealogy is what officials were told to write down and assume as the biological genealogy. It is the best possible approximation of biological genealogy possible from official records, but it is merely an approximation. A legal genealogy is an excellent basis for family history, but no reliable basis for medical decisions.

The bulk of the difference between biological and official genealogy is formed by official fathers who are not the biological father.
A small part of the difference is formed by official mothers who are not the biological mother; in most such cases the real biological mother is the oldest daughter of the ostensible biological mother. Quite often, the ostensible father really is the biological father, but in all such cases there remains the possibility that is was someone else.
An even smaller part of the difference is formed by parents who knowingly registered another couple's child as their own, thus de facto performing an adoption without acknowledging it as such.
Probably the smallest of the differences is formed by passing off a corpse as someone else.

official versus legal

The official records document the ostensible blood relationships, and many people go through life without ever being aware that the official record and blood relationship need not be the same.

The difference between an official and a legal genealogy is made by legal relationship changes such as marriage and adoption. It is not made by parents disinheriting their children; au contraire, a disinheritance actually constitutes legal acknowledgement that the children are and remain legal children.

A legal genealogy includes all legal family relationships, and that includes all marriages as well as other legal partnerships, such as legally living together. It does not include non-family partnerships such as co-founding a company together. Such information is relevant to a family history, and may explain why certain things happened, but legal genealogy is only about legal family relationships.

official genealogy

Official genealogy is different from legal genealogy in that it is the original record of vital events, unburdened by any legal changes; legal changes that either do not affect the vital relationships at all or more of than not take you further away from the biological genealogy. The official genealogy is the legal genealogy, but without any of the later changes.

Legal genealogy is the genealogy of everyday life.
legal genealogy

Legal genealogy is the genealogy of everyday life. It is how we know each other. We may not know whether the neighbour's kid were adopted, or whether they are from some previous relationship, we simply know them as their kids.

In everyday life we pretend that the legal genealogy we know is the biological genealogy, but it is actually two steps away from that; the legal genealogy contains both the lies of the original record and the deliberate legal changes done after that.



This framework has various desirable properties. An important one is that it is simple and easy to understand. Legal genealogy is how people are known, which may be different from how they were known a few years ago. Official genealogy is what the vital records say, and biological genealogy is the biological truth.


All major genealogical records have a place in this framework. The framework correctly distinguishes between vital and non-vital records, acknowledges both primary vital records (birth and death) as well as secondary vital records (baptism and burial), and correctly treats marriage records as the non-vital records they are.

That does not in any way suggest that marriage records are unimportant to official genealogy. Many older birth records identify parents vaguely, making the corresponding marriage records essential to understanding those vital records. Still, the marriage records themselves are not true vital records.

An official genealogy contains only the truly vital data; birth, death, and the official parent-child relationships. A birth record is official and legal proof of an official parent-child relationship.
A death record is official and legal proof of death. Death records are rarely used to prove relationship, but are important in disproving mistakenly assumed relationships through consistency checks.

A legal genealogy contains all family relationship. It includes all the records included in an official genealogy, and additionally includes all non-blood relationships that affect the legal right and duties of those involved. This includes marriage and adoption records.

In some cases, researchers need to be creative, and find replacements for vital records that have been lost, such as using data from grave stones. Such sourcing of vital data does not affect the conceptual framework, only the reliability of the resulting official and legal genealogy.

The official and legal genealogy remain stable in the face of discoveries about bloodlines.


Another desirable property of this framework is that it is stable. The official and legal genealogy remain stable in the face of discoveries about bloodlines. The official and legal genealogies are as stable the official and legal documents themselves; once you have built your official and legal genealogy, they do not change unless you get new documents that officially overrule previous ones.

If you discover that the biological genealogy is different from the official genealogy, you still do not changes the official or legal genealogies one bit. You do not delete or change existing lines, nor add new ones. The official and legal genealogies simply continue to correspond to the official and legal documents.
You do not change these genealogies at all, you merely edit the biological genealogy - and will probably start researching the official and legal ancestries for the newly discovered father.

family history

genealogyrecord types
family historyall records
non-vital records
vital records

A welcome property of the framework is that is easy to show how family history relates to genealogy. Genealogist generally research the legal genealogy, and that makes perfect sense; a legal genealogy is an excellent basis for family history.

Genealogy is just the facts, family history is stories. Those stories tend to include major life events such as graduation, a first job, a trip abroad, and so on. For some of these events specialised records exists. Family history uses whatever records are available, so it ultimately uses all records.

This diagram highlights that official genealogy is just the vital facts, that a legal genealogy is just all the family relationship, and that other important life events such as buying a house are not part of genealogy, but of family history.

genealogy dogmas

Two Genealogical Dogmas called attention to how two genealogical dogmas conflict with each other if you choose to believe you have just one genealogy. However, both fit in the Classical Genealogy Framework.

Official records aren't biology. Proving a biological genealogy requires biological proof.

That every child has exactly one father and one mother is true in biological genealogy and in official genealogy, it is not true in legal genealogy.

That a genealogy can be built from official and legal documents is true for official and legal genealogy only, it is not true for biological genealogy.
Official records aren't biology. Proving a biological genealogy requires biological proof.

biological proof

Observations about hair and eye colour (phenotype) and blood type can easily disprove a relationship, but are insufficient to prove a relationship. For reasonable proof of biological relationship, a genetic test is needed.

Such test have been in existence for decades and been affordable for years. However, they weren't available before that time, and relatively few people have done such a test. Even today, most people are not sure that their official father is also their biological father.
We are not living in an age of reliable biological genealogies yet.

genealogy that fits

What type of genealogy to use depends on the occasion. If you are planning a family reunion, you want the everyday facts of the legal genealogy. If you are doing DNA surname study, you want the official genealogy (but would be unwise to blindly assume all adoptees are biological unrelated). Your doctor is interested in your biological genealogy. A family historian wants the family ahnenlist, your doctor wants the birth ahnenlist.

A well-researched genealogy documented with ample source citations is a legal genealogy, not a biological one.

everyday life

Legal genealogy is the genealogy of everyday life. In everyday life, we generally act as if the legal genealogy is the biological genealogy, even though we know that position is untenable.
Many indiscretions become public secrets, but even if we know better, we pretend not to know, because pretending not to know is the socially acceptable thing to do. We continue to act as if we believe that the legal genealogy is the biological genealogy.

That our official genealogy is our biological genealogy may be what we want to be believe, but it remains just that, a belief. Phenotype such as hair colour and eye colour may corroborate that belief, but does not constitute proof. Phenotype can disprove but not prove.

A legal ancestry may not document your biological ancestors, but it does document your ancestral family.

well-researched genealogy

A well-researched genealogy documented with ample source citations is a legal genealogy, not a biological one. The official and legal sources do not prove biological relationships.
The terminology may be new, but the message should not surprise any genealogists. Still, many genealogist have trouble accepting it. Many talk about their legal or official ancestors as if they are their biological ancestors. Some will even argue vehemently that adoptees do not belong in any family tree.

Most people know who their legal parents are, but are not sure who their biological parents are.
Mature genealogists accept the vital and legal records for what they are; proof of official and legal relationships. A legal ancestry may not document your biological ancestors, but it does document your ancestral family.