Merit is required to get better/higher rank. You can read more about merit and ranks in general here:

Ranks and badges: https://bitcointalk.org/index.php?topic=178608.0
Merit: https://bitcointalk.org/index.php?topic=2818350.0

You need at least 1 merit point to get Jr. Member rank. - https://bitcointalk.org/index.php?topic=5030366.msg45810047#msg45810047