Concept:
Family is a universal social institution present in all societies.
Step 1:
Family performs important social functions such as socialization, care, and emotional support.
\[
\text{Family is a social institution}
\]
Step 2:
Family members generally live together and share social and economic life.
\[
\text{Co-habitation is commonly associated with family}
\]
Step 3:
Families are often connected with reproduction and upbringing of children.
\[
\text{Procreation is an important family function}
\]
Step 4:
Physical characteristics like height have no relation with the sociological definition of family.
\[
\text{Height is unrelated}
\]
Step 5:
Therefore, the correct answer is Height of individuals.
\[
\boxed{\text{(4) Height of individuals}}
\]