Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE person (age INTEGER)
TABLE: CREATE TABLE Person (name VARCHAR, age INTEGER)
TABLE: CREATE TABLE PersonFriend (name VARCHAR, friend VARCHAR)

### Question ###
Who has friends that are younger than the average age?

### Accurate SQL ###

SELECT DISTINCT T2.name FROM Person AS T1 JOIN PersonFriend AS T2 ON T1.name = T2.friend WHERE T1.age < (SELECT AVG(age) FROM person)