What are the different names of friends who are younger than the average age for a friend?
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)
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)
[{'name': 'Zach'}]