The Science Behind Generational Length

A generation is a specific time interval and an age location in history.

Studies by sociologist-demographers, geneticists, and population geneticists have shown that male-line generations (father to son) are longer than female-line generations (mother to daughter). The traditional 25-year interval has a new meaning today.


You can piece together family generations using genealogical research, such as birth and death certificates and old newspapers. The question “how long is a generation?” has many different answers.

When it comes to defining how long a generation lasts, there is no definitive answer. It all depends on whether you look at a family or social generation. For genealogical purposes, the length of a generation is usually defined as the period from the birth of parents to the birth of their children. This is typically 30 years but can vary depending on parents’ ages.

In a social context, a generation is defined as a cohort of individuals who share similar experiences and values. This modern definition focuses on age groups rather than the familial relationships between parents and their offspring. Sociologists generally view a social generation as having a span of about 20 years.

A genealogy researcher may use a calendar year or family line of descent to determine the length of a generation. With well-kept vital records such as birth and death certificates, tracing a generation back is easier than ever. Combining these official documents with stories found in old newspapers can help you form a complete picture of your ancestors’ lives.

With longer life expectancies and people having children later in their lives, it is becoming more challenging to define how long a generation lasts. However, most agree that there have been six generations since the beginning of the twentieth century. This includes the GI Generation, the Silent Generation, Baby Boomers, Gen X, and Millennials.


The original Bible texts used at least three words translated into English as generation. The Hebrew dor can refer to a standard, physical generation, though it can also be used metaphorically to recognize people of a distinctive type. The word toledot is also often used for this purpose, although it doesn’t imply any particular length of time.

Biological generations are based on familial relationships and span the period between the birth of parents and their children. Shared experiences, values, and beliefs distinguish this group. Social generations are groups of individuals born and raised during the same period. Historically, societies didn’t view people in terms of generations. Still, with modern methods of keeping records, such as birth and death certificates, it is now possible to see how long an individual has lived.

It can take time to determine how long a particular generation is. One method is to use the calendar year. When the last person from a specific year dies, that generation ends. However, this method can be inaccurate since many factors influence a person’s lifespan.

Other methods of determining how long a generation is include using the lifespan of a family line. Several studies have shown that male-line generations (father to son) are longer on average than female-line generations (mother to daughter). Consequently, the length of a biological or social generation can vary significantly between families.


A generation is a group of people who share similar experiences. They often have the same attitudes and behaviors as a result. Generations are also shaped by their world and their parents’ generations before them. There are two types of generations: family generations and social generations.

A family generation is a time frame that spans the years it takes for members of a family to be born, grow up, and have children. The length of a family generation varies by individual but is usually around 30 years.

The concept of social generations is relatively new and was first introduced in the late 1900s. Social generations are a way to categorize people by age. Today, six popular generations are recognized: GI, Silent, Baby Boomers, Gen X, Millennials, and Gen Z.

The Bible uses “generation” to describe a specific family tree. The genealogies in Matthew and Luke trace Jesus’s ancestry from Abraham to Joseph in 42 generations. This suggests that God defines generations differently than modern societies.


Examples of how long a generation is can help people understand the concept better. The Greatest Generation refers to the generation of Americans born between 1901 and 1927 who fought in World War II and became the subject of a best-selling book. Generally speaking, family and sociological research suggest that the average generation length is around 30 years.

However, this figure can vary depending on genetics, familial connections, and shared experiences. It’s also important to note that average generation lengths may differ between different cultures.

Another thing to remember is that a generation may be built around specific historical events. For instance, if someone’s parents met during World War II, that person would be considered a Greatest Generation member.


Gary is a lifestyle writer with a passion for healthy living, fitness, and self-improvement. His writing is dedicated to helping readers achieve their best selves through practical tips and advice.