Why do you look the way you do? Kids often look a bit like the people in their family. They do not look exactly like any one of them. The reasons are worth a closer look.

Heredity is how traits get passed down from parents to their children. A trait is a feature of a person, such as eye color. Looks such as eye color can run in a family.

Brothers and sisters from the same two parents each get a different mix. That is why they are not exactly alike. Kids with the same parents do not always look alike.

Heredity can surprise people. Parents with blue eyes can have a child with brown eyes. It is not common, but it happens. A family look does not always show up the way you would guess.

Identical twins are the closest match. They look very similar to each other. Even so, each twin is a person in their own right, shaped by how they live.

Some traits do not come from family at all. They come from the way a person lives. These are called acquired traits. Where and how a child grows up, such as at home and at school, helps shape who the child is.

Height shows both kinds at work. How tall a person grows depends on the family they come from and also on what they eat and how healthy they are. What a person eats and how much they exercise can change how they look and grow.

A child who eats well and stays active is likely to grow taller than a child with a poor diet. So the body a person gets is a mix of what was passed down and how the person lives.

Families are not all made by heredity. Some children join a family by adoption. An adopted child becomes a full and permanent member of that family. The child has the same legal rights as a child born into the family.

A blended family, also called a stepfamily, forms when two people make a life together with their children. Families come in many shapes, and each one is a family.

Words to know

• heredity: traits passed down
• traits: features
• acquired: gained by living
• adoption: joining a family
• identical: very much alike

The short version

Heredity is how traits get passed down from parents to their children. Looks such as eye color can run in a family. Brothers and sisters from the same two parents each get a different mix, so they are not exactly alike, and some traits come from how a person lives.

Quick facts

• Heredity is how traits get passed down from parents to their children.
• Parents with blue eyes can have a child with brown eyes, though it is not common.
• Identical twins look very similar to each other.
• How tall a person grows depends on the family they come from and also on what they eat and how healthy they are.
• An adopted child becomes a full and permanent member of the family.