What is the Difference Between First and Second Cousins?

The difference between first and second cousins lies in the common ancestors they share and the number of generations separating them.

• First cousins share a common grandparent, either on the maternal or paternal side. They are the children of siblings, such as aunts and uncles, and share one set of grandparents.
• Second cousins share a common great-grandparent, either on the maternal or paternal side. They are the children of first cousins and share the same great-grandparents.

In summary, first cousins share grandparents, while second cousins share great-grandparents.

Comparative Table: First vs Second Cousins

The difference between first and second cousins lies in the number of generations they are separated by and the grandparents they share. Here is a table highlighting the differences between first and second cousins:

• First cousins are non-siblings that share grandparents. They are the children of siblings and are two generations apart from each other.

• Second cousins are non-siblings that share great-grandparents. They are the children of first cousins and are three generations apart from each other.

Cousins may also have different types of removal, which indicates the number of generations separating them from each other. For example, if a first cousin is part of the same generation as you but their grandparent is your great-grandparent, they are your first cousin once removed. Conversely, if a second cousin is the same generation as you but has a great-grandparent that is your grandparent, they are your second cousin once removed.